Young Adults\u27 Human Papillomavirus–Related Knowledge: Source of Medical Information Matters

Objectives: Few studies examine the influence that different sources of medical information has on human papillomavirus (HPV)–related knowledge. We examined the relationship between the primary source of medical information and knowledge about HPV in young adults aged 18–26 years. Study design: This study used cross-sectional data from the Health Information National Trends Survey. Methods: Respondents (n = 404) self-reported their knowledge about HPV-related diseases and vaccinations and their sources of medical information. Sources of medical information included electronic/print media, family/friends, or a healthcare provider. Bivariate and multivariate analyses were used to examine the association between the source of information and HPV knowledge. Results: Fifty-six percent of respondents used electronic or print media as their primary source of medical information. A greater proportion of Hispanic (40.0%) and black (36.0%) respondents received medical information from their family/friends than white respondents (20.0%). Respondents who received medical information from family/friends had 4.34 (95% confidence interval [CI]: 2.14, 8.79), 4.06 (95% CI: 2.05, 8.04), and 2.35 (95% CI: 1.10, 5.04) times higher odds than those who received information from healthcare providers of not knowing that HPV causes cervical cancer, knowing HPV is a sexually transmitted infection, and hearing about the HPV vaccine, respectively. Conclusion: Source of medical information was significantly associated with knowledge of HPV. Receiving medical information from family/friends negatively influenced young adults\u27 HPV knowledge. These findings may guide future interventions to target peer and familial influence on medical decisions

Environmental Transmission Electron Microscopy Study of the Origins of Anomalous Particle Size Distributions in Supported Metal Catalysts

In this Environmental Transmission Electron Microscopy (ETEM) study we examined the growth patterns\u27 of uniform distributions of nanoparticles (NPs) using model catalysts. Pt/SiO2 was heated at 550 degrees C in 560 Pa of O-2 while Pd/carbon was heated in vacuum at 500 degrees C and in 300 Pa of 5%H-2 in Argon at temperatures up to 600 degrees C. Individual NPs of Pd were tracked to determine the operative sintering mechanisms. We found anomalous growth Of NPs occurred during the early stages of catalyst sintering wherein some particles started to grow significantly larger than the mean, resulting in a broadening of the particle size distribution (PSD). The abundance of the larger particles did not fit the log normal distribution. We can rule out sample nonuniformity as a cause for the growth of these large particles, since images were recorded prior to heat treatments. The anomalous growth of these particles may help explain PSDs in heterogeneous catalysts which often show particles that are significantly larger than the mean, resulting in a long tail to the right. It has been suggested previously that particle migration and coalescence could be the likely cause for such broad size distributions. We did not detect any random migration of the NPs leading to coalescence. A directed migration process was seen to occur at elevated temperatures for Pd/carbon under H-2. This study shows that anomalous growth of NPs can occur under conditions where Ostwald ripening is the primary sintering mechanism

Environmental Transmission Electron Microscopy Study of the Origins of Anomalous Particle Size Distributions in Supported Metal Catalysts

In this Environmental Transmission Electron Microscopy (ETEM) study we examined the growth patterns of uniform distributions of nanoparticles (NPs) using model catalysts. Pt/SiO₂ was heated at 550 °C in 560 Pa of O₂ while Pd/carbon was heated in vacuum at 500 °C and in 300 Pa of 5%H₂ in Argon at temperatures up to 600 °C. Individual NPs of Pd were tracked to determine the operative sintering mechanisms. We found anomalous growth of NPs occurred during the early stages of catalyst sintering wherein some particles started to grow significantly larger than the mean, resulting in a broadening of the particle size distribution (PSD). The abundance of the larger particles did not fit the log-normal distribution. We can rule out sample nonuniformity as a cause for the growth of these large particles, since images were recorded prior to heat treatments. The anomalous growth of these particles may help explain PSDs in heterogeneous catalysts which often show particles that are significantly larger than the mean, resulting in a long tail to the right. It has been suggested previously that particle migration and coalescence could be the likely cause for such broad size distributions. We did not detect any random migration of the NPs leading to coalescence. A directed migration process was seen to occur at elevated temperatures for Pd/carbon under H₂. This study shows that anomalous growth of NPs can occur under conditions where Ostwald ripening is the primary sintering mechanism