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Highly anisotropic materials show great promise for spatial control and the manipulation of polaritons. In-plane hyperbolic phonon polaritons (HPhPs) supported by α-phase molybdenum trioxide (MoO 3 ) allow for wave propagation with a high directionality due to the hyperbola-shaped isofrequency contour (IFC). However, the IFC prohibits propagations along the [001] axis, hindering information or energy flow. Here, we illustrate a novel approach to manipulating the HPhP propagation direction. We experimentally demonstrate that geometrical confinement in the [100] axis can guide HPhPs along the forbidden direction with phase velocity becoming negative. We further developed an analytical model to provide insights into this transition. Moreover, as the guided HPhPs are formed in-plane, modal profiles were directly imaged to further expand our understanding of the formation of HPhPs. Our work reveals a possibility for manipulating HPhPs and paves the way for promising applications in metamaterials, nanophotonics, and quantum optics based on natural van der Waals materials.

Objective: The aim of this study was to determine whether patients with a pain score ≥7 (high pain group) after a mandibular block injection had a higher physiologic response compared with patients with scores <7 (low pain group)., Study Design: Before oral surgery, patients (n = 66) filled out questionnaires to measure anxiety and expected pain. The questionnaires also assessed patients' experiences with dental injections and dental anxiety, as well as their emotional state and intensity of anxiety. Before, during, and after the injection, physiologic responses were measured by using Nexus-10. Patients were then asked about the pain and anxiety they had experienced., Results: The mean score for pain experienced was 3.45 (standard deviation 2.17) on an 11-point rating scale. Eight patients (12.1%) experienced high injection pain. There was a significant increase in mean sweat secretion and a significant decrease in mean respiration between the relaxing phase and the injection phase. There was a significant positive relationship between experienced anxiety and mean heart rate during the injection phase. No significant difference in physiologic response was found between patients who experienced high pain and those who experienced low pain., Conclusions: Reported pain was not associated with the physiologic response of patients receiving mandibular block injections., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Background: Shoulder pain is becoming increasingly problematic in young players as volleyball gains popularity. Associations between repetitive motion and pain and overuse injury have been observed in other overhand sports (most notably baseball). Studies of adult athletes suggest that there is a shoulder pain and overuse problem present in volleyball players, but minimal research has been done to establish rates and causes in juvenile participants., Purpose: To establish rates of shoulder pain, regardless of whether it resulted in a loss of playing time, in female high school volleyball players. A secondary goal was to determine whether high repetition volumes correlated with an increased likelihood of experiencing pain., Study Design: Descriptive epidemiology study., Methods: A self-report survey focusing on the prevalence of pain not associated with a traumatic event in female high school youth volleyball players was developed. Survey questions were formulated by certified athletic trainers, experienced volleyball coaches, and biomechanics experts. Surveys were received from 175 healthy, active high school volleyball players in Iowa, South Dakota, and Minnesota., Results: Forty percent (70/175) of active high school volleyball players remembered experiencing shoulder pain not related to traumatic injury, but only 33% (23/70) reported taking time off to recover from the pain. Based on these self-reported data, activities associated with significantly increased risk of nontraumatic shoulder pain included number of years playing competitive volleyball ( P = .01) and lifting weights out of season ( P = .001). Players who reported multiple risk factors were more likely to experience nontraumatic shoulder pain., Conclusion: When using time off for recovery as the primary injury criterion, we found that the incidence of shoulder pain is more than twice as high as the incidence of injury reported by previous studies. Findings also indicated that the incidence of shoulder pain may be correlated with volume of previous volleyball experience., Competing Interests: One or more of the authors has declared the following potential conflict of interest or source of funding: The Dordt College Center for Research and Scholarship provided the funds to mail the surveys reported on in this article.