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1.
Environ Urban ; 34(2): 446-464, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36249732

RESUMEN

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.
Artículo en Inglés | MEDLINE | ID: mdl-33638900

RESUMEN

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.


Asunto(s)
Antiinfecciosos , Hidróxido de Calcio , Antibacterianos/farmacología , Biología , Hidróxido de Calcio/farmacología , Humanos , Osteoblastos
3.
Int Endod J ; 53(9): 1264-1274, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32535966

RESUMEN

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%.


Asunto(s)
Irrigantes del Conducto Radicular , Hipoclorito de Sodio , Clorhexidina , Células Eucariotas , Humanos , Iminas , Piridinas
4.
Int Endod J ; 52(7): 979-986, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30702145

RESUMEN

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.


Asunto(s)
Antiinfecciosos , Materiales de Obturación del Conducto Radicular , Animales , Calcio , Compuestos de Calcio , Bovinos , Resinas Epoxi , Ensayo de Materiales , Silicatos
5.
Int Endod J ; 52(3): 385-392, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30220093

RESUMEN

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.


Asunto(s)
Dentina/efectos de los fármacos , Irrigantes del Conducto Radicular/farmacocinética , Hipoclorito de Sodio/farmacocinética , Raíz del Diente/efectos de los fármacos , Animales , Bovinos , Geles , Técnicas In Vitro , Soluciones , Tensoactivos/farmacología , Irrigación Terapéutica/métodos , Ultrasonido/métodos
6.
Int Endod J ; 52(6): 829-837, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30565254

RESUMEN

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.


Asunto(s)
Pulpa Dental , Heparina , Fosfatasa Alcalina , Diferenciación Celular , Proliferación Celular , Células Cultivadas , Humanos , Odontogénesis
7.
Int Endod J ; 51 Suppl 4: e264-e277, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-28134990

RESUMEN

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.


Asunto(s)
Apoptosis/efectos de los fármacos , Desinfectantes/toxicidad , Fibroblastos/efectos de los fármacos , Ácido Peracético/toxicidad , Animales , Técnicas de Cultivo de Célula , Línea Celular , Supervivencia Celular/efectos de los fármacos , Citoesqueleto/efectos de los fármacos , Fibroblastos/metabolismo , Fibroblastos/ultraestructura , Citometría de Flujo , Ratones , Microscopía Electrónica , Necrosis , Hipoclorito de Sodio/toxicidad
8.
Int Endod J ; 50(4): 352-366, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26992821

RESUMEN

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.


Asunto(s)
Enfermedades Periapicales/diagnóstico por imagen , Microtomografía por Rayos X , Animales , Ratones , Ratas , Microtomografía por Rayos X/métodos
9.
Int Endod J ; 50 Suppl 2: e31-e39, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28390072

RESUMEN

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.


Asunto(s)
Materiales Biocompatibles/farmacología , Compuestos de Calcio/farmacología , Cementos Dentales/farmacología , Osteoblastos/efectos de los fármacos , Óxidos/farmacología , Materiales de Recubrimiento Pulpar y Pulpectomía/farmacología , Silicatos/farmacología , Tantalio/farmacología , Fosfatasa Alcalina/metabolismo , Calcio/metabolismo , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Combinación de Medicamentos , Humanos , Técnicas In Vitro , Ensayo de Materiales , Sales de Tetrazolio
10.
Int Endod J ; 50(1): 39-47, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26610093

RESUMEN

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.


Asunto(s)
Compuestos de Aluminio/farmacología , Materiales Biocompatibles/farmacología , Compuestos de Calcio/farmacología , Cementos Dentales/farmacología , Osteoblastos/efectos de los fármacos , Óxidos/farmacología , Materiales de Obturación del Conducto Radicular/farmacología , Silicatos/farmacología , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Combinación de Medicamentos , Humanos , Ensayo de Materiales , Niobio/farmacología , Circonio/farmacología
11.
Int Endod J ; 50(8): 780-789, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27520288

RESUMEN

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.


Asunto(s)
Compuestos de Aluminio/farmacología , Compuestos de Calcio/farmacología , Cementos Dentales/farmacología , Pulpa Dental/citología , Osteogénesis/efectos de los fármacos , Osteogénesis/genética , Óxidos/farmacología , Materiales de Obturación del Conducto Radicular/farmacología , Silicatos/farmacología , Adolescente , Adulto , Fosfatasa Alcalina/genética , Apoptosis/efectos de los fármacos , Proteína Morfogenética Ósea 2/genética , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Pulpa Dental/efectos de los fármacos , Combinación de Medicamentos , Expresión Génica/efectos de los fármacos , Humanos , Osteocalcina/genética , ARN Mensajero/genética , Adulto Joven
12.
Genet Mol Res ; 15(4)2016 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-27886330

RESUMEN

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.


Asunto(s)
Variación Genética , Gossypium/genética , Sitios de Carácter Cuantitativo , Brasil , Fibra de Algodón , Fenotipo , Fitomejoramiento
13.
Int Endod J ; 48(5): 478-83, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-24962548

RESUMEN

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.


Asunto(s)
Precipitación Química , Clorhexidina/química , Resinas Epoxi/química , Irrigantes del Conducto Radicular/química , Hipoclorito de Sodio/química , 2-Propanol/química , Diente Canino , Cavidad Pulpar , Análisis del Estrés Dental , Dentina/química , Humanos , Técnicas In Vitro , Microscopía Electrónica de Rastreo , Preparación del Conducto Radicular , Capa de Barro Dentinario , Cloruro de Sodio/química , Agua/química
15.
J Evol Biol ; 27(12): 2727-38, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25430492

RESUMEN

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.


Asunto(s)
Adaptación Biológica/genética , Evolución Biológica , Inversión Cromosómica/genética , Drosophila/genética , Variación Genética , Modelos Genéticos , Selección Genética , Animales , Cambio Climático , Francia , Países Bajos , Portugal
16.
Ann R Coll Surg Engl ; 104(6): 400-408, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35446153

RESUMEN

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.


Asunto(s)
Tutoría , Cirujanos Ortopédicos , Ortopedia , Femenino , Humanos , Mentores , Ortopedia/educación , Estudios Prospectivos
17.
J Evol Biol ; 29(3): 672, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26957051
18.
Malays Orthop J ; 15(1): 100-104, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33880155

RESUMEN

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.
Artículo en Inglés | MEDLINE | ID: mdl-20641133

RESUMEN

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.


Asunto(s)
Colágeno/química , Simulación de Dinámica Molecular , Pericardio/química , Animales , Isótopos de Carbono , Bovinos , Espectroscopía de Resonancia Magnética/normas , Estructura Molecular , Estándares de Referencia
20.
Food Res Int ; 137: 109435, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-33233116

RESUMEN

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.


Asunto(s)
Productos de la Carne , Gases em Plasma , Antioxidantes , Italia , Productos de la Carne/análisis , Extractos Vegetales
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