No abstract available.
Fatigue*

OBJECTIVES: The aim of this study was to compare the mechanical properties of various nickel-titanium (NiTi) files with similar tapers and cross-sectional areas depending on whether they were surface-treated. MATERIALS AND METHODS: Three NiTi file systems with a similar convex triangular cross-section and the same ISO #25 tip size were selected for this study: G6 (G6), ProTaper Universal (PTU), and Dia-PT (DPT). To test torsional resistance, 5 mm of the straightened file's tip was fixed between polycarbonate blocks (n = 15/group) and continuous clockwise rotation until fracture was conducted using a customized device. To evaluate cyclic fatigue resistance, files were rotated in an artificial curved canal until fracture in a dynamic mode (n = 15/group). The torsional data were analyzed using 1-way analysis of variance and the Tukey post-hoc comparison test, while the cyclic fatigue data were analyzed using the Mann-Whitney U test at a significance level of 95%. RESULTS: PTU showed significantly greater toughness, followed by DPT and G6 (p < 0.05). G6 showed the lowest resistance in ultimate torsional strength, while it showed a higher fracture angle than the other files (p < 0.05). In the cyclic fatigue test, DPT showed a significantly higher number of cycles to failure than PTU or G6 (p < 0.05). CONCLUSIONS: Within the limitations of this study, it can be concluded that the torsional resistance of NiTi files was affected by the cross-sectional area, while the cyclic fatigue resistance of NiTi files was influenced by the surface treatment.
Fatigue

Listening effort is defined as a listener's mental exertion required to understand a speaker's auditory message, especially when distracting conditions are present. This review paper analyzed several subjective scaling tools used to measure the listening effort in order to suggest the best tool for use with hearing-impaired listeners who have to expend much effort even in everyday life. We first explained the importance of measuring listening effort and discussed various kinds of measurements. We then analyzed and categorized 15 recently published articles (i.e., from 2014 to 2016) into three topics: performance and listening effort, listening effort and fatigue, and clinical implication of listening effort. We compared the articles in terms of pros and cons and also identified 10 tools for use in the subjective scaling. Although none of these tools were unified or standardized easily, we concluded that 7-point scale would be the most reasonable as a less time-consuming measurement for compartmentalizing the degree of listening effort. If used with objective tools for measuring the listening effort, the subjective scaling could be a powerful tool for clinical use.
Fatigue

No abstract available.
Fatigue*

No abstract available.
Fatigue* ; Sciatica*

No abstract available.
Fatigue* ; Thorax*

No abstract available.
Fatigue* ; Thorax*

Fatigue is a universally common word. The subject has been studied in different disciplines, but the basic concept of the term still remains unidentified. It becomes especially important for the medical communications between nurses and clients. Based on the framework outlined by Walker and Avant(1995), this analysis attempts to clarify and examine the symptoms of fatigue. The attributes of fatigue identified in this paper were exhaustion, weighted psychological burden, shortage in capacity or lack of energy, shortage incapacity(motivation and excitement), and imbalance of energy. Therefore, the definition of fatigue refers to a subjective feeling from various internal or external stresses. The consequences of fatigue bring reduced capacity and imbalance of energy. The symptoms show a homeostatic disability or shortage of capacity (physical, psychological, environmental and physiological factors). A precise understanding of 'fatigue' will be utilized in defining the causes and measuring outcomes. Also, it will enhance the effective medical communications with clients and nurses. In conclusion, more work is needed to develop objective measurement and effective nursing intervention.
Fatigue* ; Nursing

PURPOSE: To compare ocular fatigue, non-ocular symptoms, and ocular surface changes, such as tear break-up time (BUT) and ocular surface temperature, after watching 2-dimensional (2D) and 3-dimensional (3D) images. METHODS: Fourteen volunteers were enrolled in the present study. Subjects watched 2D as well as 3D images and answered questions regarding ocular fatigue and general symptoms such as headache. Before and after watching images, the spherical equivalent, degree of conjunctival injection, tear BUT, and ocular surface temperature were measured and the amount of change was analyzed. While watching images, subjects answered questions regarding ocular fatigue and the time when they began to feel definitive symptoms. RESULTS: Watching 3D images induced a greater degree of ocular fatigue, headache, and decreasing concentration than watching 2D images (p = 0.038, 0.003, and 0.045, respectively). While watching images, 3D images induced a greater degree of ocular fatigue than 2D images and caused subjects to feel earlier ocular fatigue (3D: 54.86 min, 2D: 78.57 min, p = 0.002). Spherical equivalents became more myopic after watching 3D images. CONCLUSIONS: After watching 3D images, a greater degree of ocular fatigue, headache, and decreasing concentration was induced and a shorter time to feel definitive ocular fatigue was observed than after watching 2D images. In addition, spherical equivalents changed myopically after watching 3D images.
Fatigue ; Headache

OBJECTIVES: This study compared the cyclic fatigue resistance of nickel-titanium (NiTi) files obtained in a conventional test using a simulated canal with a newly developed method that allows the application of constant fatigue load conditions. MATERIALS AND METHODS: ProFile and K3 files of #25/.06, #30/.06, and #40/.04 were selected. Two types of testing devices were built to test their fatigue performance. The first (conventional) device prescribed curvature inside a simulated canal (C-test), the second new device exerted a constant load (L-test) whilst allowing any resulting curvature. Ten new instruments of each size and brand were tested with each device. The files were rotated until fracture and the number of cycles to failure (NCF) was determined. The NCF were subjected to one-way ANOVA and Duncan's post-hoc test for each method. Spearman's rank correlation coefficient was computed to examine any association between methods. RESULTS: Spearman's rank correlation coefficient (rho = -0.905) showed a significant negative correlation between methods. Groups with significant difference after the L-test divided into 4 clusters, whilst the C-test gave just 2 clusters. From the L-test, considering the negative correlation of NCF, K3 gave a significantly lower fatigue resistance than ProFile as in the C-test. K3 #30/.06 showed a lower fatigue resistance than K3 #25/.06, which was not found by the C-test. Variation in fatigue test methodology resulted in different cyclic fatigue resistance rankings for various NiTi files. CONCLUSIONS: The new methodology standardized the load during fatigue testing, allowing determination fatigue behavior under constant load conditions.
Androsterone ; Fatigue