RESUMO
Macromolecular scaffolds are rapidly emerging in catalysis owing to the ability to control catalyst placement at precise locations. This spatial proximity allows for enhanced catalyst activity that may not be observed using small molecules. Herein, we describe a triphenylpyrylium (TPT)-based visible-light active single-chain polymer nanoparticle (SCNP) that facilitates the radical cation [4 + 2]-cycloaddition. We find that the catalytic activity is highly dependent on the styrylarene comonomer used, wherein it can act as a redox mediator under confinement, increasing the catalytic turnover (TON) by up to 30 times in comparison to free TPT in solution. Mechanistic studies indicate that TPT excited states are quenched by the acene, with the resultant radical cation formed from naphthalene-based SCNPs able to proceed in oxidizing the dienophile in the elementary step of the reaction, while leading to near quantitative yields of the cycloadduct. The TPT-SCNP demonstrates enhanced photocatalyst efficiency compared to molecular TPT, and is able to be recycled and reused in three iterations of the reaction prior to decreased performance from photobleaching. Our results overall suggest that the confined nature of the SCNP and spatial proximity of acene-based pendants enforces their participation as cocatalytic redox mediators that impart enhanced photoredox catalysis under confinement.
RESUMO
Introducción: El uso diario de ayudas para la higiene oral y la profilaxis oral anual o semestral por parte de los profesionales de la odontología (dentistas, higienistas dentales, asistentes dentales) son dos maneras efectivas de mantener una buena higiene oral. El presente estudio se llevó a cabo para evaluar el conocimiento, la actitud y la práctica sobre higiene bucal entre higienistas dentales que trabajan en el oeste de Maharashtra, India. Materiales y métodos: se realizó un estudio de cuestionario entre 52 higienistas dentales en activo de diferentes áreas del oeste de Maharashtra. Se diseñó un cuestionario estructurado, cerrado autoadministrado para recopilar los datos que constaba de dos partes y comprendía 31 preguntas. Se hizo un análisis estadístico utilizando estadísticas descriptivas. Resultados: En este estudio, más del 50% de los participantes conocían la importancia del mantenimiento de la higiene bucal y los diferentes tipos de ayudas para la higiene bucal y correctos métodos de uso de esas ayudas para la higiene oral. Alrededor del 96% de los participantes pensaba que la técnica de cepillado adecuada es necesaria para mantener una buena higiene bucal. Conclusión: El conocimiento general, la actitud y la práctica de los participantes del estudio con respecto a las ayudas para la higiene bucal se observaron en un nivel promedio.
Introduction: Everyday use of oral hygiene aids and annual or biannual oral prophylaxis by dental professionals (Dentists, Dental hygienists, Dental assistants) are two effective ways of maintaining good oral hygiene. The present study was conducted to assess the knowledge, attitude, and practice about oral hygiene among working dental hygienists in Western Maharashtra, India. Materials and methods: A questionnaire study was conducted among 52 working dental hygienists from different areas of Western Maharashtra. The structured, self-administered, close-ended questionnaire was designed to collect the data which consist of two parts and comprised 31 questions. Statistical analysis was done using descriptive statistics. Results: In this study, more than 50% of participants were known the importance of oral hygiene maintenance and different types of oral hygiene aids and correct methods of using those oral hygiene aids. About 96% participants thought that proper brushing technique is necessary to maintain good oral hygiene. Conclusion: The study participant's overall knowledge, attitude and practise regarding oral hygiene aids were seen at average level.