The Effect of Endodontic Solutions on Resorcinol-Formalin Paste in Teeth

This study determined if any of six endodontic solutions would have a softening effect on resorcinol-formalin paste in extracted teeth, and if there were any differences in the solvent action between these solutions. Forty-nine single-rooted extracted teeth were decoronated two mm coronal to the CEJ, and the roots sectioned apically to a standard length of 15 mm. Canals were prepared to a 12mm WL and a uniform size with a #7 Parapost drill. Teeth were then mounted in a cylinder ring with acrylic. The resorcinol-formalin mixture was placed into the canals and was allowed to set for 60 days in a humidor. The solutions tested were 0.9% sodium chloride, 5.25% sodium hypochlorite, chloroform, Endosolv R®, 3% hydrogen peroxide, and 70% isopropyl alcohol. Seven samples per solution were tested and seven samples using water served as controls. One drop of the solution was placed over the set mixture in the canal, and the depth of penetration of a 1.5 mm probe was measured at 2, 5, 10, and 20 min using a dial micrometer gauge. A repeated-measures ANOVA showed a difference in penetration between the solutions at 10 min (p=0.04) and at 20 min (p=0.0004). At 20 min, Endosolv R®, had significantly greater penetration than 5.25% sodium hypochlorite (p=0.0033) and chloroform (p=0.0018); however, it was not significantly better than the control (p=0.0812). Although Endosolv R®, had statistically superior probe penetration at 20 min, the softening effect could not be detected clinically at this time

A biomechanical comparison of two relay starts in swimming

The purpose of this investigation was to identify the mechanical characteristics of the steop start in relay competition and to compare this start to a traditional relay start

Experiences and Perceptions of Rural Junior High Teachers Participating in a Professional Learning Community

In this qualitative descriptive case study, the researcher investigated how junior high school teachers’ perceptions of the role of how professional learning communities (PLCs) shaped their instructional practices in a rural Title I school in Texas. Exploring and understanding the experiences and perceptions of the teachers and administrators that participated in an English, language arts, and reading PLC provided valuable data that helped the administration determine professional development opportunities that could improve the instructional strategies of the teachers. By collaborating, analyzing student data, and sharing teaching strategies, the teachers were empowered to take ownership and improve their instructional practices. Examining the teachers’ perceptions and experiences revealed the strengths and weaknesses of the local program and provided an opportunity to personalize professional development to increase teacher learning as well as student achievement. Furthermore, the researcher identified and analyzed barriers to develop a plan of action to increase stronger team bonding. Keywords: professional learning communities; collaboration; shared mission, vision, and values; collective inquiry; continuous improvement; results orientatio

Effects of variable zinc and oxygen concentrations on the optical properties of gallium phosphide single crystals

Two series of crystals were considered in this work. One contained variable zinc with constant oxygen while the other contained variable oxygen with constant zinc

Modification of electronic surface states by graphene islands on Cu(111)

We present a study of graphene/substrate interactions on UHV-grown graphene islands with minimal surface contamination using \emph{in situ} low-temperature scanning tunneling microscopy (STM). We compare the physical and electronic structure of the sample surface with atomic spatial resolution on graphene islands versus regions of bare Cu(111) substrate. We find that the Rydberg-like series of image potential states is shifted toward lower energy over the graphene islands relative to Cu(111), indicating a decrease in the local work function, and the resonances have a much smaller linewidth, indicating reduced coupling to the bulk. In addition, we show the dispersion of the occupied Cu(111) Shockley surface state is influenced by the graphene layer, and both the band edge and effective mass are shifted relative to bare Cu(111).Comment: 12 pages, 3 figure

Perceptions of Stress, Mindfulness, and Occupational Engagement Among Graduate-level Occupational Therapy Students

Previous literature explored the concepts of stress, mindfulness, and occupational engagement, yet there is a substantial gap linking these terms within the field of occupational therapy (OT). The researchers identified a need to investigate the perceptions of these concepts among graduate-level OT students and its impact on their quality of life and occupational balance. Current research identified mindfulness and occupational engagement as healthy coping strategies for reducing stress and both concepts emphasized the action of being fully present and engaged. The exploratory mixed-methods study consisted of 490 students from graduate-level OT programs throughout the United States. Results revealed that the majority of participants experienced high levels of stress while in graduate school. The findings indicated that stress, academic responsibilities, and limited application of coping strategies impacted the ability to engage in meaningful activities. Participants identified mindfulness as an effective coping mechanism, which included strategies of deep breathing, journaling, and meditation in addition to the act of being mindful through self-reflection and self-awareness. Although participants reported positive views of mindfulness to decrease stress, the reported use did not appear to alter the participants’ perceptions of quality of life. Findings suggested a lack of occupational engagement in meaningful activities negatively impacted the participants’ perceived quality of life and occupational balance. The study provided support for strengthening the connection between the constructs of mindfulness and occupational engagement. The study has broad implications for the field of OT and its applicability to stress management in both academic and professional settings