Impact of Event Scale-6 (IES-6) for U.S. adults who experienced the COVID-19 pandemic.

BACKGROUND: COVID-19 pandemic causes psychological problems such as stress. It is important to accurately identify the level of stress and establish effective intervention. The Impact of Event Scale-6 (IES-6) is widely used for post-traumatic stress disorder (PTSD) screening by measuring the level of subjective stress, but there has been no research on its psychometric properties with individuals who experienced the COVID-19 pandemic. METHODS: A random sample of 600 participants were randomly selected from a COVID-19 survey database (n = 6391). Rasch analysis was conducted to examine item fit, rating scale structure, construct validity, differential item functioning (DIF), and precision of the IES-6. RESULTS: The principal component analysis of Rasch residuals (54.1% of the raw variance explained) and the average of residual correlations (average r = .19) supported the unidimensionality structure in the IES-6. The rating scale was suitable, and the item difficulty hierarchy was logical. The item fit and the DIF contrast were acceptable, except for item 5. The IES-6's person reliability was .76, which was also an acceptable level. CONCLUSIONS: This study showed that the IES-6 has acceptable item-level psychometrics for screening the stress level in adults in the United States for individuals who have experienced the COVID-19 pandemic. The findings suggested that the IES-6 would be useful for the rapid identification of the high-level stressand allow clinicians to quickly provide interventions for people with the COVID-19 related stress and their families.

Effect of Cooling Rate on Mechanical Properties, Translucency, Opalescence, and Light Transmission Properties of Monolithic 4Y-TZP during Glazing.

A standard cooling rate has not been established for glazing; therefore, the effects of the cooling rate on the properties of zirconia need to be evaluated to predict outcomes in clinical practice. 4Y-TZP glazed at three different cooling rates was analyzed to estimate the effect of cooling rate during glazing on the mechanical and optical properties. Hardness tests, field-emission scanning electron microscopy analysis, X-ray diffraction analysis, flexural strength measurement, and optical property evaluations were performed. When 4Y-TZP was glazed at a higher cooling rate (Cooling-1) than the normal cooling rate (Cooling-2), there was no significant difference in grain size, flexural strength, average transmittance, and translucency parameters. The hardness was slightly reduced. The opalescence parameter was reduced for the 2.03 mm thick specimens. When 4Y-TZP was glazed at a lower cooling rate (Cooling-3) than the normal cooling rate, there was no significant difference in hardness, grain size, flexural strength, and translucency parameters. In addition, the average transmittance and opalescence parameters were slightly reduced for the 0.52 and 2.03 mm specimens, respectively. The effects of the cooling rate during glazing on the mechanical and optical properties of 4Y-TZP appear to be minimal and clinically insignificant. Therefore, even if the cooling rate cannot be strictly controlled during glazing, the clinical outcomes will not be significantly affected.

Genetic influences on mammographic density in Korean twin and family: the Healthy Twin study.

Higher mammographic density is a strong risk factor for breast cancer. This study was conducted to determine the role of genetic factors on mammographic density measurements in Korean women. Study subjects were 730 women (122 monozygotic (MZ) twin pairs, 28 dizygotic (DZ) twin pairs, and 430 first degree relatives) from the Healthy Twin study. Mammographic density was measured using a computer-assisted method. Pairwise correlations of residual variance of each component of mammographic density were calculated within each pair of twins and family members. Quantitative genetic analysis was completed using SOLAR. Age and measured covariates accounted for 50% of the variation in dense area, 70% of non-dense area, and 67% of percent dense area. Fully adjusted heritability coefficients for dense area, non-dense area, and percent dense area were 0.76 (SE = 0.04), 0.69 (SE = 0.04) and 0.68 (SE = 0.04), respectively. Pairwise correlation coefficients of the adjusted residual variance of the mammographic density measures within MZ pairs and within DZ and sibling pairs combined were, respectively, 0.70 and 0.28 for dense area, 0.52 and 0.31 for non-dense area, and 0.58 and 0.24 for percent dense area. Covariance between dense and non-dense area had a significant genetic basis (correlation coefficient = -0.25, SE = 0.06). The same high heritability of mammographic density in Korean women as found in Western women supports a significant role of genetic determinants in breast cancer development. Genes that are responsible for familial correlation in mammographic density and have opposite effects on dense and non-dense mammographic areas need to be elucidated.