Colorimetric Sensor Based on Hydroxypropyl Cellulose for Wide Temperature Sensing Range.

Recently, temperature monitoring with practical colorimetric sensors has been highlighted because they can directly visualize the temperature of surfaces without any power sources or electrical transducing systems. Accordingly, several colorimetric sensors that convert the temperature change into visible color alteration through various physical and chemical mechanisms have been proposed. However, the colorimetric temperature sensors that can be used at subzero temperatures and detect a wide range of temperatures have not been sufficiently explored. Here, we present a colorimetric sensory system that can detect and visualize a wide range of temperatures, even at a temperature below 0 °C. This system was developed with easily affordable materials via a simple fabrication method. The sensory system is mainly fabricated using hydroxypropyl cellulose (HPC) and ethylene glycol as the coolant. In this system, HPC can self-assemble into a temperature-responsive cholesteric liquid crystalline mesophase, and ethylene glycol can prevent the mesophase from freezing at low temperatures. The colorimetric sensory system can quantitatively visualize the temperature and show repeatability in the temperature change from -20 to 25 °C. This simple and reliable sensory system has great potential as a temperature-monitoring system for structures exposed to real environments.

Factors Influencing Pain and Anxiety Before Endodontic Treatment: A Cross-Sectional Study Amongst American Individuals.

OBJECTIVE: The present study aimed to assess preoperative levels of patient anxiety and pain before root canal treatment, and to explore variables that may affect these levels. METHODS: Ninety-five patients presenting for an endodontic visit were recruited for the study. A questionnaire was administered. Visual analog scales were used to record levels of pain and anxiety. Data was tabulated, and analysis was performed using the Pearson Chi-Squire test with continuity correction, and the level of significance was set at 0.05 (P=0.05). RESULTS: Anxiety was detected more frequently in females (60%) than in males (33%) (P=0.016). Sixty-two percent of patients who were waiting for a new treatment were anxious, compared to 39% of those who were returning to continue treatment (P=0.049). Sixty-nine percent of patients in pain reported being anxious (P=0.015). Patients aged 18-30 years reported more pain than those older than 30 years (P=0.023). Forty-three percent of new patients reported being in pain, whereas only 20% of patients returning for a treatment reported pain (P=0.027). CONCLUSION: Anxiety associated with root canal treatment is prevalent, and it was reported primarily by young females who were presenting for a new treatment. Pain and anxiety are highly inter-related, and they are usually reduced after the first endodontic session.