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1.
Environ Urban ; 34(2): 446-464, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36249732

RESUMO

How do ordinary citizens, activists and urban practitioners learn to become agents of change for a socially just habitat? The paper explores this question through the experiences of eight grassroots schools of popular urbanism working under the umbrella of the Habitat International Coalition (HIC) in Latin America. Building on a process of self-documentation and collective pedagogic reflection driven by the protagonists of these schools, the analysis explores the core pedagogic practices identified across the schools to enact popular urbanism as a collective and intentional praxis: to weave, sentipensar, mobilize, reverberate and emancipate. We argue that, put in motion, these pedagogic practices transgress the rules and boundaries of the formal classroom, taking participants to and through other sites and modes of learning that host significant potential to stimulate collectivizing and alternative ways of seeking change towards urban equality.

2.
Int Endod J ; 54(7): 1155-1165, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33638900

RESUMO

AIM: To analyse the antimicrobial and biological properties of a new bioceramic intracanal medicament (Bio-C Temp), and to compare it with two calcium hydroxide-based intracanal medicaments (Calen® and UltraCal® XS). METHODOLOGY: The direct contact and the crystal violet tests were performed to assess the antimicrobial activity of intracanal medicaments against Enterococcus faecalis. The cytocompatibility and the effect of the medication on the biology of the human osteoblast-like cell line (Saos-2) were evaluated with methylthiazole tetrazolium (MTT), neutral red, alkaline phosphatase activity and mineralization (alizarin red) assays. The data were analysed using one-way anova and Tukey's tests, two-way anova and Bonferroni's tests, or Kruskal-Wallis and Dunn's tests (α = 0.05). RESULTS: Bio-C Temp had significantly less antibacterial activity and biofilm biomass reduction than the other intracanal medicaments (P < 0.05). There was no difference in the viability of Saos-2 exposed to the various intracanal medicaments, except regarding the 1 : 2 dilution, when the Bio-C Temp group had significantly lower cell viability than the UltraCal® XS and Calen® groups (P < 0.05). Bio-C Temp induced significantly greater ALP activity than the other intracanal medicaments (P < 0.05) at day 1. Calen® induced significantly greater deposition of mineralized nodules than the other intracanal medicaments (P < 0.05), and no difference was observed between Bio-C Temp and UltraCal® XS (P > 0.05). CONCLUSIONS: Bio-C Temp had similar cytocompatibility at higher dilutions, and higher or similar induction of ALP activity and deposition of mineralized nodules in comparison with Calen® and UltraCal® XS. However, it had significantly less antibacterial and antibiofilm activity than Calen® and UltraCal® XS.


Assuntos
Anti-Infecciosos , Hidróxido de Cálcio , Antibacterianos/farmacologia , Biologia , Hidróxido de Cálcio/farmacologia , Humanos , Osteoblastos
3.
Int Endod J ; 53(9): 1264-1274, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32535966

RESUMO

AIM: To assess the effects of octenidine dihydrochloride (OCT) on eukaryotic cells and the cytotoxicity of OCT associated with sodium hypochlorite - NaOCl (NaOCl/OCT). METHODOLOGY: L929 fibroblasts and human osteoblast-like cells (Saos-2) were exposed to 0.1% OCT, 2% CHX, 2.5% NaOCl, 5.25% NaOCl and mixtures of 5.25% NaOCl and 0.1% OCT (NaOCl/OCT) at 90 : 10, 80 : 20 and 50 : 50 ratios. Cell viability was assessed by methyl-thiazol-tetrazolium (MTT) and neutral red (NR) assays; type of cell death, by flow cytometry; cytoskeleton, by actin and α-tubulin fluorescence; and alkaline phosphatase (ALP) activity, by thymolphthalein release. The data were analysed by two-way ANOVA and Bonferroni tests (α = 0.05). RESULTS: MTT and NR assays revealed that 0.1% OCT had the lowest cytotoxicity (P < 0.05), followed by 2% CHX (P < 0.05). The 2.5% NaOCl, NaOCl/OCT 80 : 20 and NaOCl/OCT 50 : 50 solutions had intermediate cytotoxicity. NaOCl 5.25% and NaOCl/OCT 90 : 10 had the highest cytotoxicity (P < 0.05). The OCT group had a higher percentage of viable cells than the NaOCl and CHX groups (P < 0.05), and induced apoptosis at higher doses. The cytoskeleton alterations were observed at 0.12%, 0.6% and 2.02% for the NaOCl, CHX and OCT groups, respectively. The solutions did not induce ALP activity. CONCLUSION: Octenidine dihydrochloride was less cytotoxic, induced apoptosis at higher doses, caused few changes in the cytoskeleton and did not induce alkaline phosphatase activity. In addition, octenidine dihydrochloride reduced the cytotoxicity of 5.25% NaOCl when combined at 20 and 50%.


Assuntos
Irrigantes do Canal Radicular , Hipoclorito de Sódio , Clorexidina , Células Eucarióticas , Humanos , Iminas , Piridinas
4.
Int Endod J ; 52(7): 979-986, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30702145

RESUMO

AIM: To evaluate the cytocompatibility, bioactive potential, antimicrobial and antibiofilm activities of an experimental calcium silicate-based endodontic sealer, in comparison with TotalFill BC Sealer and AH Plus. METHODOLOGY: Cytocompatibility was assessed by methyltetrazolium (MTT) and neutral red (NR) assays, after exposure of the Saos-2 cells to the sealer extracts (1 : 2, 1 : 4, 1 : 8, 1 : 16 and 1 : 32 dilutions) for 24 h. The sealers were manipulated and placed in 12-well culture plates and exposed to ultraviolet light; then, 5 mL of DMEM without serum was added. Cell bioactivity was evaluated by alkaline phosphatase activity (ALP) and Alizarin red staining (ARS). Antimicrobial and antibiofilm activities were evaluated by direct contact test (DCT) on planktonic cells (DCTPC) and modified DCT on biofilm formed in bovine dentine blocks (MDCT). MTT, NR and ALP data were analysed by two-way anova and Bonferroni tests; ARS data by anova and Tukey's tests; and the microbiological data by Kruskal-Wallis and Dunn tests (α = 0.05). RESULTS: The experimental sealer, TotalFill BC and AH Plus were not cytotoxic to Saos-2, in comparison with the negative control (P > 0.05). Greater ALP was observed after 7 days of exposure of Saos-2 to AH Plus and the experimental sealer (P < 0.05) when compared to the control. Significantly greater mineralized nodule production was observed for TotalFill BC and the experimental sealer (P < 0.05). In DCTPC, the experimental sealer and TotalFill BC were associated with a significantly greater reduction of E. faecalis (P < 0.05) and eliminated C. albicans. In MDCT, the experimental sealer and TotalFill BC had significantly greater antibiofilm efficacy (P < 0.05). CONCLUSIONS: The experimental calcium silicate-based sealer was cytocompatible, bioactive, antimicrobial against E. faecalis and C. albicans and effective against E. faecalis biofilms, with potential for use in root canal treatment.


Assuntos
Anti-Infecciosos , Materiais Restauradores do Canal Radicular , Animais , Cálcio , Compostos de Cálcio , Bovinos , Resinas Epóxi , Teste de Materiais , Silicatos
5.
Int Endod J ; 52(3): 385-392, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30220093

RESUMO

AIM: To assess the penetration of sodium hypochlorite (NaOCl) gel or NaOCl solutions with surfactants, and the effect of passive ultrasonic irrigation (PUI) on penetration into dentinal tubules. METHODOLOGY: Bovine incisor root canals were instrumented, the roots sectioned and the dentine blocks obtained were stained with crystal violet. Dentine blocks (n = 10 per group) were exposed to 3% NaOCl gel or 3% NaOCl solution for 10 and 20 min. Other dentine blocks (n = 10 per group) were exposed to Chlor-Extra (6% NaOCl + surfactant), 6% NaOCl, 2.5% NaOCl with 0.2% cetrimide and 2.5% NaOCl for 10 and 20 min. The penetration depth of irrigants into dentinal tubules was measured in micrometres by viewing the bleached crystal violet under a stereomicroscope. Additionally, bovine incisor root canals, instrumented and stained with crystal violet, were distributed into two groups (n = 10) and irrigated with 2.5% NaOCl with PUI or conventional syringe irrigation (CSI). The penetration depth of irrigants into dentinal tubules was assessed 3 and 7 mm from the apex. Statistical analysis was performed by ANOVA and Tukey tests (α = 0.05). RESULTS: There was significantly greater penetration of 3% NaOCl solution into dentinal tubules compared with the gel form (P < 0.05). There was no difference (P > 0.05) between 6% NaOCl and Chlor-Extra, and between 2.5% NaOCl and 2.5% NaOCl + cetrimide. PUI significantly increased the penetration depth of NaOCl into dentinal tubules when compared with CSI (P < 0.05). CONCLUSIONS: In extracted bovine incisors, NaOCl gel penetrated less into dentinal tubules than NaOCl solution. The addition of surfactants did not increase the penetration depth. The use of PUI significantly increased NaOCl penetration into dentinal tubules.


Assuntos
Dentina/efeitos dos fármacos , Irrigantes do Canal Radicular/farmacocinética , Hipoclorito de Sódio/farmacocinética , Raiz Dentária/efeitos dos fármacos , Animais , Bovinos , Géis , Técnicas In Vitro , Soluções , Tensoativos/farmacologia , Irrigação Terapêutica/métodos , Ultrassom/métodos
6.
Int Endod J ; 52(6): 829-837, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-30565254

RESUMO

AIM: To investigate the biocompatibility, osteogenic bioactivity and mRNA expression of the osteo/odontogenic markers bone morphogenetic protein 2 (BMP-2), osteocalcin (OC) and alkaline phosphatase (ALP), induced by heparin in human dental pulp cells (hDPCs). METHODOLOGY: hDPCs were exposed to the heparin, and cell viability was assessed by 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide (MTT), and cell death was evaluated by flow cytometry. Osteogenic bioactivity was evaluated by the alkaline phosphatase (ALP) assay, and the detection of calcium deposits by alizarin red staining (ARS). The gene expression of BMP-2, OC and ALP was quantified with real-time PCR. Statistical analysis was performed with ANOVA and Bonferroni or Tukey post-test and t-test (α = 0.05). RESULTS: Heparin had no cytotoxic effect and did not induce apoptosis. After 3 days, heparin had significantly higher ALP activity in comparison with the control (P < 0.05). Heparin had a significant (P < 0.05) stimulatory effect on the formation of mineralized nodules. BMP-2 and OC mRNA expressions were significantly higher in cells exposed to heparin than control group after 1 day (P < 0.05). CONCLUSIONS: Heparin was biocompatible in hDPCs, induced osteogenic bioactivity and enhanced mRNA expression of osteo/odontogenic markers BMP-2 and OC. These results suggest that heparin has potential to induce osteo/odontogenic cell differentiation of hDPCs.


Assuntos
Polpa Dentária , Heparina , Fosfatase Alcalina , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Humanos , Odontogênese
7.
Int Endod J ; 51 Suppl 4: e264-e277, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28134990

RESUMO

AIM: To evaluate the cytotoxicity and the mechanism of cell aggression of peracetic acid (PA) in comparison with sodium hypochlorite (NaOCl). METHODOLOGY: L929 fibroblasts were exposed to 1% PA and 2.5% NaOCl, at several dilutions for 10 min. The following parameters were evaluated: cell metabolism by methylthiazol tetrazolium assay, external morphology by scanning electron microscopy, ultrastructure by transmission electron microscopy, the cytoskeleton by means of actin and α-tubulin labelling, and the type of cell death by flow cytometry (apoptosis/necrosis). The data were analysed by two-way anova and the Bonferroni post-test (α = 0.05). RESULTS: The PA group had lower cell viability and a higher percentage of necrotic cells than the NaOCl group (P < 0.05). Both solutions diminished cell metabolism, led to destructuring of the cytoskeleton, created changes in the external morphology, resulted in the accumulation of proteins in the rough endoplasmic reticulum and induced cell death predominantly by necrosis. However, these changes were observed in lower doses of PA when compared with NaOCl. CONCLUSIONS: Although they had the same mechanism of cytotoxicity, 1% PA had greater cytotoxic potential than 2.5% NaOCl.


Assuntos
Apoptose/efeitos dos fármacos , Desinfetantes/toxicidade , Fibroblastos/efeitos dos fármacos , Ácido Peracético/toxicidade , Animais , Técnicas de Cultura de Células , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Citoesqueleto/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/ultraestrutura , Citometria de Fluxo , Camundongos , Microscopia Eletrônica , Necrose , Hipoclorito de Sódio/toxicidade
8.
Int Endod J ; 50(4): 352-366, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26992821

RESUMO

This systematic review aimed to evaluate the literature on the acquisition-, reconstruction- and analysis parameters of micro-computed tomography (micro-CT) for the assessment of periapical lesions in rats and mice, and to illustrate the effect of variation in these parameters. The PubMed database was searched from 2000 to January 2015 (English-language publications) for reports on the use of micro-CT to evaluate periapical lesions in rats and mice. QUADAS criteria were used to rate the quality of the studies. To illustrate the effect of variations in acquisition-, reconstruction-, and analysis parameters on images of periapical lesions, micro-CT examination of two hemi-mandibles of mice, with periapical lesions around the first molar was undertaken. Twenty-one studies were identified, which analysed periapical lesions in rats or mice using micro-CT. According to the QUADAS, no study was classified as high-, seven were classified as moderate-, and 14 as low quality. The effect of variation in parameters was that voxel size may interfere with image sharpness, reconstruction may interfere with image sharpness and contrast, and inadequate plane orientation may alter the size of the periapical lesion. Nonpersonalized ROIs resulted in areas that were not part of the periapical lesion. Changing the limits of the threshold for bone-tissue visualization increased lesion size. There is no defined protocol for acquiring and analysing micro-CT images of periapical lesions in rats and mice. Furthermore, acquisition-, reconstruction- and analysis parameters are not adequately explained, which may compromise the scientific impact of the studies.


Assuntos
Doenças Periapicais/diagnóstico por imagem , Microtomografia por Raio-X , Animais , Camundongos , Ratos , Microtomografia por Raio-X/métodos
9.
Int Endod J ; 50(1): 39-47, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26610093

RESUMO

AIM: To compare the bioactivity of Biodentine (BIO, Septodont), MTA Plus (MTA P, Avalon) and calcium silicate experimental cement (CSC) with resin (CSCR) associated with zirconium (CSCR ZrO2 ) or niobium (CSCR Nb2 O5 ) oxide as radiopacifiers. METHODOLOGY: According to the relevance of osteoblastic cell response for mineralized tissue repair, human osteoblastic cells (Saos-2) were exposed to test materials and assessed for viability (MTT), cell proliferation, gene expression of alkaline phosphatase (ALP) osteogenic marker by real-time PCR (RT-qPCR), ALP activity assay and alizarin red staining (ARS) to detect mineralization nodule deposition in osteogenic medium. Unexposed cells acted as the control group (C). Statistical analysis was carried out using ANOVA and the Bonferroni post-test (P < 0.05). RESULTS: All tested cements showed dose-dependent responses in cell viability (MTT). Exposed cells revealed good viability (80-130% compared to the control group) in the highest dilutions of all types of cement. MTA P, BIO and CSCR ZrO2 significantly increased the velocity of cell proliferation after three days of cell exposure in the wound-healing assay (P < 0.05), which corroborated MTT data. On day 3, the ALP transcript level increased, especially to CSCR Nb2 O5 (P < 0.05). All cements exhibited suitable ALP enzyme activity, highlighting the 7-day period of cell exposure. ARS, CSCR Nb2 O5 , revealed a significant potential to induce mineralization in vitro. CONCLUSIONS: All materials had suitable biocompatibility and bioactivity. The MTA P, BIO and CSCR ZrO2 groups had the highest viability rates and velocity of proliferation whilst the CSCR Nb2 O5 group produced more mineralized nodules.


Assuntos
Compostos de Alumínio/farmacologia , Materiais Biocompatíveis/farmacologia , Compostos de Cálcio/farmacologia , Cimentos Dentários/farmacologia , Osteoblastos/efeitos dos fármacos , Óxidos/farmacologia , Materiais Restauradores do Canal Radicular/farmacologia , Silicatos/farmacologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Combinação de Medicamentos , Humanos , Teste de Materiais , Nióbio/farmacologia , Zircônio/farmacologia
10.
Int Endod J ; 50 Suppl 2: e31-e39, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28390072

RESUMO

AIM: To evaluate the biocompatibility and mineralized nodule formation of an experimental tricalcium silicate cement with tantalum oxide (TSC/Ta2 O5 ) as radiopacifier, Neo MTA Plus (Avalon Biomed Inc., Bradenton, FL, USA) and MTA (Angelus, Londrina, PR, Brazil) on human osteoblast-like cells (Saos-2). METHODOLOGY: Biocompatibility was evaluated by 3-(4,5-dimethyl-thiazoyl)-2,5-diphenyl-tetrazolium bromide (MTT) and neutral red (NR) assays, after exposure of Saos-2 to cement extracts at 1 : 1, 1 : 2, 1 : 4 and 1 : 8 dilutions for 24 h. Bioactivity was evaluated by alkaline phosphatase (ALP) activity, and calcium deposits were detected with alizarin red staining (ARS). Statistical analysis was performed with analysis of variance and Bonferroni or Tukey post-test (α = 0.05). RESULTS: The MTT assay revealed lower cytotoxicity for NEO and MTA (P < 0.05), and higher for TSC/Ta2 O5 at 1 : 1 and 1 : 2 dilutions when compared to serum-free medium - control (P > 0.05). At 1 : 4 dilution, the TSC/Ta2 O5 cytotoxicity was similar to the control (P > 0.05). At 1 : 8 dilution, cell viability was significantly greater than the control (P < 0.05). Saos-2 cell viability performed using the NR assay at all dilutions revealed no cytotoxic effect of MTA, NEO and TSC/Ta2 O5 . ALP activity at 1 and 3 days was similar to the control (P > 0.05). TSC/Ta2 O5 had significantly greater ALP activity at 7 days when compared with the control (P < 0.05). All materials induced the production of mineralized nodules, and NEO produced significantly more mineralized nodules than MTA and TSC/Ta2 O5 (P < 0.05). CONCLUSIONS: Neo MTA Plus and TSC/Ta2 O5 were biocompatible and induced ALP activity in Saos-2 cells. Both materials induced mineralized nodule formation by Saos-2 with Neo MTA Plus producing significantly more.


Assuntos
Materiais Biocompatíveis/farmacologia , Compostos de Cálcio/farmacologia , Cimentos Dentários/farmacologia , Osteoblastos/efeitos dos fármacos , Óxidos/farmacologia , Agentes de Capeamento da Polpa Dentária e Pulpectomia/farmacologia , Silicatos/farmacologia , Tantálio/farmacologia , Fosfatase Alcalina/metabolismo , Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Combinação de Medicamentos , Humanos , Técnicas In Vitro , Teste de Materiais , Sais de Tetrazólio
11.
Int Endod J ; 50(8): 780-789, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27520288

RESUMO

AIM: To investigate the cytotoxicity, osteogenic bioactivity and mRNA expression of osteogenic markers of bone morphogenetic protein 2 (BMP-2), osteocalcin (OC) and alkaline phosphatase (ALP) induced by the extracts of set MTA Plus (MTA P) (Avalon Biomed Inc. Bradenton, FL, USA) in comparison with MTA (Angelus, Londrina, PR, Brazil) on human dental pulp cells (hDPCs). METHODOLOGY: Cell viability was assessed by mitochondrial dehydrogenase enzymatic (MTT) assay, and the mechanism of cell death was evaluated by flow cytometry. Bioactivity was evaluated by alkaline phosphatase (ALP) assay and detection of calcium deposits with alizarin red staining (ARS). The gene expression of BMP-2, OC and ALP was quantified with real-time PCR. Statistical analysis was performed with analysis of variance and Bonferroni or Tukey post-test (α = 0.05). RESULTS: MTA and MTA P were not cytotoxic and did not induce apoptosis. MTA P had significant higher ALP activity in relation to MTA and the control (P < 0.05). MTA had a significantly higher percentage of mineralized area than MTA P (P < 0.05). The expression of BMP2 and OC mRNA was significantly higher in cells exposed to MTA than MTA P after 1 day (P < 0.05). At day 3, the mRNA expression of ALP was significantly higher in MTA P compared with MTA (P < 0.05). CONCLUSIONS: MTA and MTA Plus were noncytotoxic, increased mineralization processes in vitro and induced the expression of osteogenic markers.


Assuntos
Compostos de Alumínio/farmacologia , Compostos de Cálcio/farmacologia , Cimentos Dentários/farmacologia , Polpa Dentária/citologia , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Óxidos/farmacologia , Materiais Restauradores do Canal Radicular/farmacologia , Silicatos/farmacologia , Adolescente , Adulto , Fosfatase Alcalina/genética , Apoptose/efeitos dos fármacos , Proteína Morfogenética Óssea 2/genética , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Polpa Dentária/efeitos dos fármacos , Combinação de Medicamentos , Expressão Gênica/efeitos dos fármacos , Humanos , Osteocalcina/genética , RNA Mensageiro/genética , Adulto Jovem
12.
Genet Mol Res ; 15(4)2016 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-27886330

RESUMO

Brazil is among the five largest producers of cotton in the world, cultivating the species Gossypium hirsutum L. r. latifolium Hutch. The cultivars should have good fiber quality as well as yield. Genetic improvement of fiber traits requires the study of the genetic structure of the populations under improvement, leading to the identification of promising parent plants. To this end, it is important to acquire some information, such as estimates of genetic variance components and heritability coefficients, which will support the appropriate choice of the breeding strategy to be employed as well as enable the estimation of gains from selection. This study aimed to evaluate some agronomic characteristics, such as fiber quality and yield, estimating genetic parameters for the purpose of predicting earnings. Twelve cultivars of cotton, including four male progenitors (CNPA 01-42, BRS Verde, Glandless, and Okra leaf) and eight female progenitors (Delta opal, CNPA 7H, Aroeira, Antares, Sucupira, Facual, Precoce 3, and CNPA 8H), were used in performing crosses according to design I, proposed by Comstock and Robinson (1948). The experimental design was a randomized block with four replications. We observed genetic variability among all traits as well as higher efficiency of selection for the gains related to traits. Our results showed that the combined selection presented the highest genetic gains for all traits. For fiber length, the female/male selection and the combined selection resulted in the highest genetic gain.


Assuntos
Variação Genética , Gossypium/genética , Locos de Características Quantitativas , Brasil , Fibra de Algodão , Fenótipo , Melhoramento Vegetal
13.
Int Endod J ; 48(5): 478-83, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-24962548

RESUMO

AIM: To evaluate the effectiveness of isopropyl alcohol, saline or distilled water to prevent the precipitate formed between sodium hypochlorite (NaOCl) and chlorhexidine (CHX) and its effect on the bond strength of an epoxy-based sealer in radicular dentine. METHODOLOGY: The root canals of 50 extracted human canines (n = 10) were instrumented. In G1, root canals were irrigated with 17% EDTA and 2.5% NaOCl; G2, as G1, except that 2% CHX was used as the final irrigant. In the other groups, intermediate flushes with isopropyl alcohol (G3), saline (G4) or distilled water (G5) were used between NaOCl and CHX. The specimens were submitted to SEM analysis to evaluate the presence of debris and smear layer, in the apical and cervical segments. In sequence, fifty extracted human canines were distributed into five groups (n = 10), similar to the SEM study. After root filling, the roots were sectioned transversally to obtain dentine slices, in the cervical, middle and apical thirds. The root filling was submitted to a push-out bond strength test using an electromechanical testing machine. Statistical analysis was performed using Kruskal-Wallis and Dunn's tests (α = 5%). RESULTS: All groups had similar amounts of residue precipitated on the canal walls (P > 0.05). The push-out bond strength values were similar for all groups, independently of the root third evaluated (P > 0.05). CONCLUSIONS: Isopropyl alcohol, saline and distilled water failed to prevent the precipitation of residues on canal walls following the use of NaOCl and CHX. The residues did not interfere with the push-out bond strength of the root filling.


Assuntos
Precipitação Química , Clorexidina/química , Resinas Epóxi/química , Irrigantes do Canal Radicular/química , Hipoclorito de Sódio/química , 2-Propanol/química , Dente Canino , Cavidade Pulpar , Análise do Estresse Dentário , Dentina/química , Humanos , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Preparo de Canal Radicular , Camada de Esfregaço , Cloreto de Sódio/química , Água/química
15.
J Evol Biol ; 27(12): 2727-38, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25430492

RESUMO

Chromosomal inversions are present in a wide range of animals and plants, having an important role in adaptation and speciation. Although empirical evidence of their adaptive value is abundant, the role of different processes underlying evolution of chromosomal polymorphisms is not fully understood. History and selection are likely to shape inversion polymorphism variation to an extent yet largely unknown. Here, we perform a real-time evolution study addressing the role of historical constraints and selection in the evolution of these polymorphisms. We founded laboratory populations of Drosophila subobscura derived from three locations along the European cline and followed the evolutionary dynamics of inversion polymorphisms throughout the first 40 generations. At the beginning, populations were highly differentiated and remained so throughout generations. We report evidence of positive selection for some inversions, variable between foundations. Signs of negative selection were more frequent, in particular for most cold-climate standard inversions across the three foundations. We found that previously observed convergence at the phenotypic level in these populations was not associated with convergence in inversion frequencies. In conclusion, our study shows that selection has shaped the evolutionary dynamics of inversion frequencies, but doing so within the constraints imposed by previous history. Both history and selection are therefore fundamental to predict the evolutionary potential of different populations to respond to global environmental changes.


Assuntos
Adaptação Biológica/genética , Evolução Biológica , Inversão Cromossômica/genética , Drosophila/genética , Variação Genética , Modelos Genéticos , Seleção Genética , Animais , Mudança Climática , França , Países Baixos , Portugal
16.
Ann R Coll Surg Engl ; 104(6): 400-408, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35446153

RESUMO

INTRODUCTION: Trauma and orthopaedics is renowned for being a challenging yet rewarding career. The value of mentorship in medical and surgical training is known to be beneficial; however, the prevalence and quality of mentorship opportunities in orthopaedics are less well studied. Identifying the strengths and weaknesses of mentoring programmes in orthopaedic training and recognising barriers to effective mentorship are key to unlocking the full potential of future orthopaedic surgeons. METHODS: A comprehensive search of PubMed, Medline, EMBASE and the Cochrane Library was performed. All studies published in the English language that reported data on mentorship programmes in orthopaedic training were included. FINDINGS: A total of 23 studies met the inclusion criteria. These studies demonstrated that formal mentorship programmes in orthopaedics are lacking but are sought after, with a positive influence on satisfaction and future career choice/subspecialty selection identified. Several barriers to mentoring in the field were recognised including the difficulty faced by female trainees, the availability of mentors and time constraints. The opportunity to choose a mentor, a mentor with the same interests, regular meetings and the option of gender congruent mentorship were all identified as crucial requirements for effective mentorship. CONCLUSION: Mentorship opportunities must be more accessible to all orthopaedic trainees alike and should aim to incorporate the attributes identified to provide the highest calibre of training to prospective orthopaedic surgeons.


Assuntos
Tutoria , Cirurgiões Ortopédicos , Ortopedia , Feminino , Humanos , Mentores , Ortopedia/educação , Estudos Prospectivos
17.
J Evol Biol ; 29(3): 672, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26957051
18.
Malays Orthop J ; 15(1): 100-104, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33880155

RESUMO

INTRODUCTION: COVID-19 has had a significant impact on the entire health system. The trauma and orthopaedic service has been compelled to alter working practices to respond proactively and definitively to the crisis. The aim of this study is to summarise the impact of this outbreak on the trauma and orthopaedic workload and outline the response of the department. MATERIALS AND METHODS: We retrospectively collected data comparing patient numbers pre-COVID-19, and prospectively during the early COVID-19 pandemic. We have collected the numbers and nature of outpatient orthopaedic attendances to fracture clinics and elective services, inpatient admissions and the number of fracture neck of femur operations performed. RESULTS: The number of outpatient attendances for a musculoskeletal complaint to Accident and Emergency and the number of virtual fracture clinic reviews reduced by almost 50% during COVID-19. The number of face-to-face fracture clinic follow-ups decreased by around 67%, with a five-fold increase in telephone consultations. Inpatient admissions decreased by 33%, but the average number of fracture neck of femur operations performed has increased by 20% during COVID-19 compared to pre-COVID-19 levels. CONCLUSION: We have noted a decrease in some aspects of the trauma and orthopaedic outpatient workload, such as leisure and occupational-related injuries but an increase in others, such as fracture neck of femurs. Many injuries have significantly reduced in numbers and we consider that a model could be developed for treating these injuries away from the acute hospital site entirely, thereby allowing the acute team to focus more appropriate major trauma injuries.

19.
Magn Reson Chem ; 48(9): 704-11, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20641133

RESUMO

This article describes a solid-state NMR (SSNMR) investigation of the influence of hydration and chemical cross-linking on the molecular dynamics of the constituents of the bovine pericardium (BP) tissues and its relation to the mechanical properties of the tissue. Samples of natural phenethylamine-diepoxide (DE)- and glutaraldehyde (GL)-fixed BP were investigated by (13)C cross-polarization SSNMR to probe the dynamics of the collagen, and the results were correlated to the mechanical properties of the tissues, probed by dynamical mechanical analysis. For samples of natural BP, the NMR results show that the higher the hydration level the more pronounced the molecular dynamics of the collagen backbone and sidechains, decreasing the tissue's elastic modulus. In contrast, in DE- and GL-treated samples, the collagen molecules are more rigid, and the hydration seems to be less effective in increasing the collagen molecular dynamics and reducing the mechanical strength of the samples. This is mostly attributed to the presence of cross-links between the collagen plates, which renders the collagen mobility less dependent on the water absorption in chemically treated samples.


Assuntos
Colágeno/química , Simulação de Dinâmica Molecular , Pericárdio/química , Animais , Isótopos de Carbono , Bovinos , Espectroscopia de Ressonância Magnética/normas , Estrutura Molecular , Padrões de Referência
20.
Food Res Int ; 137: 109435, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33233116

RESUMO

The effect of the glow discharge cold plasma pretreatment (CPT) was investigated on the ultrasound-assisted extraction (UAE) of phenolic compounds from sea asparagus Salicornia neei. The extract was applied in dry fermented sausage (Italian salami). Thermal extraction methods demand a long processing time, are highly energy-consuming and cause irreversible nutrient losses. It was found that CPT (discharge power of 14 W for 5 min) prior to UAE increased the antioxidant activity by 22% and 19% measured by the DPPH and ABTS assays, respectively. The S. neei extract showed high antioxidant activity, low antimicrobial activity, and was added to salami formulations with reduced-sodium nitrite content and no addition of sodium erythorbate. Despite a slight color change, lipid oxidation and texture parameters were similar to the control at the end of ripening. Furthermore, higher antioxidant activity was observed in S. neei extract supplemented salami with no impact on its sensory overall acceptability, indicating its potential as a natural alternative to synthetic additives.


Assuntos
Produtos da Carne , Gases em Plasma , Antioxidantes , Itália , Produtos da Carne/análise , Extratos Vegetais
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