Characterization of novel calcium hydroxide- mediated highly porous chitosan- calcium scaffolds for potential application in dentin tissue engineering

The aim of this study was to develop a highly porous calcium- containing chitosan scaffold suitable for dentin regeneration. A calcium hydroxide (Ca[OH]2) suspension was used to modulate the degree of porosity and chemical composition of chitosan scaffolds. The chitosan solution concentration and freezing protocol were adjusted to optimize the porous architecture using the phase- separation technique. Scanning electron microscopy/energy- dispersive spectroscopy demonstrated the fabrication of a highly porous calcium- linked chitosan scaffold (CH- Ca), with a well- organized and interconnected porous network. Scaffolds were cross- linked on glutaraldehyde (GA) vapor. Following a 28- day incubation in water, cross- linked CH scaffold had no changes on humid mass, and CH- Ca featured a controlled degradability profile since the significant humid mass loss was observed only after 21 (26.0%) and 28- days (42.2%). Fourier- transform infrared spectroscopy indicated the establishment of Schiff base on cross- linked scaffolds, along with calcium complexation for CH- Ca. Cross- linked CH- Ca scaffold featured a sustained Ca2+ release up to 21- days in a humid environment. This porous and stable architecture allowed for human dental pulp cells (HDPCs) to spread throughout the scaffold, with cells exhibiting a widely stretched cytoplasm; whereas, the cells seeded onto CH scaffold were organized in clusters. HDPCs seeded onto CH- Ca featured significantly higher ALP activity, and gene expressions for ALP, Col1, DMP- 1, and DSPP in comparison to CH, leading to a significant 3.5 times increase in calcium- rich matrix deposition. In sum, our findings suggest that CH- Ca scaffolds are attractive candidates for creating a highly porous and bioactive substrate for dentin tissue engineering.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/155906/1/jbmb34586.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/155906/2/jbmb34586_am.pd

Fidedignidade e validade de construto do Teste de Aprendizagem Auditivo-Verbal de Rey em idosos brasileiros

BACKGROUND: The Rey Auditory-Verbal Learning Test (RAVLT) is widely used for the assessment of episodic memory. However, there are few studies in Brazil assessing its psychometric properties. OBJECTIVES: To search for evidence of reliability and construct validity of the RAVLT, and to assess the influence of age, schooling, gender, and depressive symptoms on test performance. METHODS: One hundred twenty-six healthy older adults (aged 60 and over) performed the RAVLT, Mini-Mental State Exam (MMSE), Clock Drawing Test (CDT) and the Geriatric Depression Scale. Reliability was assessed by analysis of internal consistency, and construct validity by factor analysis and correlations with the MMSE and CDT. The influence of age, schooling and depressive symptoms was estimated by conducting linear regression analysis, and the role of gender by comparing the performance of males and females. RESULTS: The RAVLT showed a high internal consistency, weak correlations with the MMSE and CDT, and a bifactorial structure, which is related to the processes of learning and episodic memory retrieval. Only age and gender affected test performance. DISCUSSION: Our results provide evidence of reliability and construct validity in the tested RAVLT version, attesting its potential for clinical and research purposes for the Brazilian elderly population.CONTEXTO: O Teste de Aprendizagem Auditivo-Verbal de Rey (RAVLT) é amplamente utilizado para a avaliação da memória episódica. Suas propriedades psicométricas, porém, não foram bem analisadas no Brasil. OBJETIVOS: Buscar evidências de fidedignidade e validade de construto do RAVLT e analisar a influência de idade, gênero, escolaridade e sintomas depressivos no desempenho. MÉTODOS: Cento e vinte e seis idosos saudáveis realizaram o RAVLT, o Miniexame do Estado Mental (MEEM), o Desenho do Relógio (DR) e a Escala de Depressão Geriátrica. A fidedignidade foi avaliada pela análise de consistência interna e a validade de construto, pela estrutura fatorial e correlações com o MEEM e o DR. A influência da idade, escolaridade e sintomas depressivos foi estimada mediante regressão linear, enquanto diferenças de gênero foram avaliadas comparando o desempenho de homens e mulheres. RESULTADOS: O teste apresenta alta consistência interna e estrutura bifatorial relacionada aos processos de armazenamento e evocação da memória episódica. O teste mostrou, em geral, correlações fracas com o MEEM e o DR. Apenas a idade e o gênero influenciaram o desempenho na tarefa. CONCLUSÃO: Nossos resultados indicam que a versão do RAVLT analisada apresenta bons indícios de fidedignidade e validade de construto, atestando sua aplicabilidade em contextos clínicos e de pesquisa para a população estudada

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Nanotubos de dióxido de titânio como reforço de um cimento resinoso autoadesivo na fase de polimerização química

Objective: This study has analyzed bond strength to root dentine and to fiberglass posts, and the radiopacity of self-adhesive dual resin cement in addition of titanium dioxide nanotubes (nt-TiO2) in self-curing polymerization. Material and Methods: The self-adhesive resin cement (RelyX U200TM, 3M ESPE) was enhanced with different concentrations (0.3, 0.6, and 0.9% by weight) of nt-TiO2 and evaluated at only self-curing mode. To test the bond strength to root dentine and fiberglass posts was applied the push out bond strength test (PO). To analyze the radiopacity was follow the ISO standard (9917-2/2010). Data were statistically analyzed by one-way ANOVA test, followed by post hoc multiple comparisons Fishers test for PO and Tukeys test for RO (p<0.05). Results: Reinforced self-adhesive resin cement influenced the increase in values of PO, especially in the S06 group (0.6 wt%), which demonstrated a higher value of bond strength, mainly in the apical third. However, this analysis not demonstrated statistical difference between the groups with nt-TiO2 addition (S03, S06 and S09) and the control group (SCT). For radiopacity, the addition of nt-TiO2 may provide an increase in value, especially to the S09 group, which showed a higher value with statistical difference in comparison with SCT group. Conclusion: The addition of nt- TiO2 showed influence at behavior of the self-cure mode of the self-adhesive resin cement, and its use in other concentrations may be considered for future studies, since reinforced cement may prove better results in indirect restorative procedures.Objetivo: Este estudo analisou a resistência de união à dentina radicular e aos pinos de fibra de vidro, e a radiopacidade de um cimento resinoso dual autoadesivo com a adição de nanotubos de dióxido de titânio (nt-TiO2) na sua fase de polimerização química. Material e métodos: O cimento resinoso auto-adesivo (RelyX U200TM, 3M ESPE) foi reforçado com diferentes concentrações de nt-TiO2 (0,3, 0,6, and 0,9% em peso) e avaliado somente em seu modo de polimerização química. Para avaliar a resistência de união à dentina radicular e aos pinos de fibra de vidro foi aplicado o teste push out (PO). Para a análise da radiopacidade (RO) foi seguido o padrão ISO (9917- 2/2010). Os dados foram submetidos à análise estatística por ANOVA seguido de comparações múltiplas de Fisher para PO e Tukey para RO (p<0,05). Resultados: O cimento resinoso autoadesivo reforçado influenciou no aumento dos valores de PO, em especial no grupo S06 (0,6% em peso), o qual demonstrou um maior valor de resistência de união, principalmente no terço apical. Entretanto essa análise não apresentou diferença estatística entre os grupos com a adição de nt- TiO2 (S03, S06 e S09) e o grupo controle (SCT). Para radiopacidade, a adição de nt- TiO2 promoveu um aumento em valores, especialmente para S09, que mostrou um maior valor com diferença estatística em comparação com SCT. Conclusão: A adição de nt-TiO2 mostrou influência no comportamento do modo de polimerização química do cimento resinoso autoadesivo, e seu uso em outras concentrações pode ser considerado para futuros estudos, já que o cimento reforçado pode revelar resultados superiores em procedimentos restauradores indiretos

Nanotubos de dióxido de titânio como reforço de um cimento resinoso autoadesivo na fase de polimerização química

Objective: This study has analyzed bond strength to root dentine and to fiberglass posts, and the radiopacity of self-adhesive dual resin cement in addition of titanium dioxide nanotubes (nt-TiO2) in self-curing polymerization. Material and Methods: The self-adhesive resin cement (RelyX U200TM, 3M ESPE) was enhanced with different concentrations (0.3, 0.6, and 0.9% by weight) of nt-TiO2 and evaluated at only self-curing mode. To test the bond strength to root dentine and fiberglass posts was applied the push out bond strength test (PO). To analyze the radiopacity was follow the ISO standard (9917-2/2010). Data were statistically analyzed by one-way ANOVA test, followed by post hoc multiple comparisons Fishers test for PO and Tukeys test for RO (p<0.05). Results: Reinforced self-adhesive resin cement influenced the increase in values of PO, especially in the S06 group (0.6 wt%), which demonstrated a higher value of bond strength, mainly in the apical third. However, this analysis not demonstrated statistical difference between the groups with nt-TiO2 addition (S03, S06 and S09) and the control group (SCT). For radiopacity, the addition of nt-TiO2 may provide an increase in value, especially to the S09 group, which showed a higher value with statistical difference in comparison with SCT group. Conclusion: The addition of nt- TiO2 showed influence at behavior of the self-cure mode of the self-adhesive resin cement, and its use in other concentrations may be considered for future studies, since reinforced cement may prove better results in indirect restorative procedures.Objetivo: Este estudo analisou a resistência de união à dentina radicular e aos pinos de fibra de vidro, e a radiopacidade de um cimento resinoso dual autoadesivo com a adição de nanotubos de dióxido de titânio (nt-TiO2) na sua fase de polimerização química. Material e métodos: O cimento resinoso auto-adesivo (RelyX U200TM, 3M ESPE) foi reforçado com diferentes concentrações de nt-TiO2 (0,3, 0,6, and 0,9% em peso) e avaliado somente em seu modo de polimerização química. Para avaliar a resistência de união à dentina radicular e aos pinos de fibra de vidro foi aplicado o teste push out (PO). Para a análise da radiopacidade (RO) foi seguido o padrão ISO (9917- 2/2010). Os dados foram submetidos à análise estatística por ANOVA seguido de comparações múltiplas de Fisher para PO e Tukey para RO (p<0,05). Resultados: O cimento resinoso autoadesivo reforçado influenciou no aumento dos valores de PO, em especial no grupo S06 (0,6% em peso), o qual demonstrou um maior valor de resistência de união, principalmente no terço apical. Entretanto essa análise não apresentou diferença estatística entre os grupos com a adição de nt- TiO2 (S03, S06 e S09) e o grupo controle (SCT). Para radiopacidade, a adição de nt- TiO2 promoveu um aumento em valores, especialmente para S09, que mostrou um maior valor com diferença estatística em comparação com SCT. Conclusão: A adição de nt-TiO2 mostrou influência no comportamento do modo de polimerização química do cimento resinoso autoadesivo, e seu uso em outras concentrações pode ser considerado para futuros estudos, já que o cimento reforçado pode revelar resultados superiores em procedimentos restauradores indiretos

A new megaflora (leaves and reproductive structures) from the Huancané Formation (Lower Cretaceous), Peru

We describe fossil leaves and reproductive structures remains from the Lower Cretaceous of Peru. A great part of the plant fossils are very well preserved, and they come from three different stratigraphic levels of the Huancane Formation in a single locality close to Cusco City. The fossil flora is dominated by Brachyphyllum, Cupressinocladus, Podozamites, leaves assigned to the Araucariaceae and Araucarites Presl. Other leaf fossil-genera found are: Weichselia, Sagenopteris, Sphenopteris, and Pachypteris. This fossil assemblage is consistent with the age inferred for the Huancane Formation, which was based on biostratigraphic and isotopic studies. The plant assemblage suggests a forest canopy dominated by conifers, with an understore composed by ferns (Weichselia) and putative pteridosperms. These new data increase the knowledge of the palaeofloristic composition of the Cretaceous flora of Peru, contribute to the fossil record of South America, and particularly to the palaeoflora near equatorial regions.Fil: Martinez, Leandro Carlos Alcides. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Botánica Darwinion. Academia Nacional de Ciencias Exactas, Físicas y Naturales. Instituto de Botánica Darwinion; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Pacheco Huacallo, Edgar. Universidad Nacional San Antonio Abad del Cusco; PerúFil: Pujana, Roberto Roman. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; ArgentinaFil: Padula, Horacio. Gobierno de la Ciudad de Buenos Aires. Subsecretaria de Cultura. Patrimonio E Instituto Historico; Argentin

Conciliar o útil ao agradável e fazer ciência: Jardim Botânico do Rio de Janeiro - 1808 a 1860 Joining pleasure and work in the making science: the Jardim Botânico do Rio de Janeiro - 1808 to 1860

Embora esteja às vésperas de completar duzentos anos, a trajetória do Jardim Botânico do Rio de Janeiro ainda carece de estudo sistematizado. O artigo busca compreender as questões que ocasionaram o desinteresse por esse estabelecimento científico nas pesquisas da história das ciências e das instituições, acarretando a permanência do que consta em memória elaborada pelo seu diretor João Barbosa Rodrigues, por ocasião do centenário da instituição. Analisa as principais questões relacionadas à sua história desde a criação em 1808, até sua incorporação pelo Imperial Instituto Fluminense de Agricultura, em 1861, com o objetivo de colaborar para as discussões acerca da história das instituições e das ciências naturais, no período em foco.<br>Jardim Botânico do Rio de Janeiro played an important role in the first half of the nineteenth century. Although the park will soon celebrate its two-hundredth anniversary, no systematized study of it has ever been undertaken. With the intent of contributing to discussions on the history of institutions and the natural sciences during the period in question, the article seeks to uncover what has lain behind this disinterest in the Garden on the part of researchers from the history of the sciences and history of institutions. The article also analyzes major issues in the history of the Garden from its creation in 1808 until becoming part of the Imperial Instituto Fluminense de Agricultura in 1861