Understanding How Older Adults Comprehend COVID-19 Interactive Visualizations via Think-Aloud Protocol

Older adults have been hit disproportionally hard by the COVID-19 pandemic. One critical way for older adults to minimize the negative impact of COVID-19 and future pandemics is to stay informed about its latest information, which has been increasingly presented through online interactive visualizations (e.g., live dashboards and websites). Thus, it is imperative to understand how older adults interact with and comprehend online COVID-19 interactive visualizations and what challenges they might encounter to make such visualizations more accessible to older adults. We adopted a user-centered approach by inviting older adults to interact with COVID-19 interactive visualizations while at the same time verbalizing their thought processes using a think-aloud protocol. By analyzing their think-aloud verbalizations, we identified four types of thought processes representing how older adults comprehended the visualizations and uncovered the challenges they encountered with these thought processes. Furthermore, we also identified the challenges they encountered with seven common types of interaction techniques adopted by the visualizations. Based on the findings, we present design guidelines for making interactive visualizations more accessible to older adults.</p

A Highly Selective Fluorescent Sensor for Distinguishing Cadmium from Zinc Ions Based on a Quinoline Platform

A fluorescent sensor, <i>N</i>-(quinolin-8-yl)-2-(quinolin-8-yloxy)­acetamide (<b>HL</b>), based on 8-aminoquinoline and 8-hydroxyquinoline platforms has been synthesized. This sensor displays high selectivity and sensitive fluorescence enhancement to Cd²⁺ in ethanol. Moreover, sensor <b>HL</b> can distinguish Cd²⁺ from Zn²⁺ via two different sensing mechanisms (photoinduced electron transfer for Cd²⁺; internal charge transfer for Zn²⁺). The composition of the complex Cd²⁺/<b>HL</b> or Zn²⁺/<b>L</b>^– has been found to be 1:1, based on the fluorescence/absorption titration and further confirmed by X-ray crystallography

A Highly Selective Fluorescent Sensor for Distinguishing Cadmium from Zinc Ions Based on a Quinoline Platform

A fluorescent sensor, <i>N</i>-(quinolin-8-yl)-2-(quinolin-8-yloxy)­acetamide (<b>HL</b>), based on 8-aminoquinoline and 8-hydroxyquinoline platforms has been synthesized. This sensor displays high selectivity and sensitive fluorescence enhancement to Cd²⁺ in ethanol. Moreover, sensor <b>HL</b> can distinguish Cd²⁺ from Zn²⁺ via two different sensing mechanisms (photoinduced electron transfer for Cd²⁺; internal charge transfer for Zn²⁺). The composition of the complex Cd²⁺/<b>HL</b> or Zn²⁺/<b>L</b>^– has been found to be 1:1, based on the fluorescence/absorption titration and further confirmed by X-ray crystallography

Water-Soluble Colorimetric and Ratiometric Fluorescent Probe for Selective Imaging of Palladium Species in Living Cells

A novel water-soluble colorimetric and ratiometric fluorescent probe was synthesized and applied to imaging palladium species under physiological conditions in phosphate buffered saline (PBS) containing less than 1% organic cosolvent without adding any additional reagents. Based on palladium triggered terminal propargyl ethers cleavage reaction, the probe exhibited a high selectivity and sensitivity for palladium species of all the typical oxidation states (0, +2, +4), with a low detection limit (25 nM, 2.7 μg/L) and an obvious color change. Furthermore, the probe was successfully used for ratiometric fluorescence imaging of palladium in living cells