Healthcare personnel with severe acute respiratory coronavirus virus 2 (SARS-CoV-2) infection were interviewed to describe activities and practices in and outside the workplace. Among 2,625 healthcare personnel, workplace-related factors that may increase infection risk were more common among nursing-home personnel than hospital personnel, whereas selected factors outside the workplace were more common among hospital personnel.

Within the central nervous system (CNS), antigen-presenting cells (APCs) play a critical role in orchestrating inflammatory responses where they present CNS-derived antigens to immune cells that are recruited from the circulation to the cerebrospinal fluid, parenchyma, and perivascular space. Available data indicate that APCs do so indirectly from outside of CNS vessels without direct access to luminal contents. Here, we applied high-resolution, dynamic intravital two-photon laser scanning microscopy to directly visualize extravascular CX3CR1+ APC behavior deep within undisrupted CNS tissues in two distinct anatomical sites under three different inflammatory stimuli. Surprisingly, we observed that CNS-resident APCs dynamically extend their cellular processes across an intact vessel wall into the vascular lumen with preservation of vessel integrity. While only a small number of APCs displayed intravascular extensions in intact, noninflamed vessels in the brain and the spinal cord, the frequency of projections increased over days in an experimental autoimmune encephalomyelitis model, whereas the number of projections remained stable compared to baseline days after tissue injury such as CNS tumor infiltration and aseptic spinal cord trauma. Our observation of this unique behavior by parenchyma CX3CR1+ cells in the CNS argues for further exploration into their functional role in antigen sampling and immune cell recruitment.

Nanorod arrays of chromium (Cr) were grown on glassy carbon (GC) electrodes by a dc magnetron sputtering glancing angle deposition (GLAD) technique. The Cr nanorods were used as low-cost, high surface area, metallic supports for a conformal layer of Pt thin film catalyst, as a potential low-loading electrocatalyst for the oxygen reduction reaction (ORR) in polymer electrolyte membrane (PEM) fuel cells. A dc magnetron sputtering small angle deposition (SAD) technique was utilized for a conformal coating of Pt on Cr nanorods. The ORR activity of SAD-Pt/GLAD-Cr electrodes was investigated using cyclic voltammetry (CV) and rotating-disk electrode (RDE) techniques in a 0.1 M HClO4 solution at room temperature. A reference sample consisting of GLAD Cr nanorods coated with a Pt thin film deposited at normal incidence (θ = 0o) was prepared and compared with the SAD-Pt/GLAD-Cr nanorods. Compared to GLAD Cr nanorods coated with Pt thin film at θ = 0o, the SAD-Pt/GLAD-Cr nanorod electrode exhibited higher ECSA and area-specific and mass-specific ORR activity. These results indicate that the growth of catalyst layer on the base-metal nanorods by the SAD technique provides a more conformal and possibly a nanostructured coating, significantly enhancing the catalyst utilization.

In this work, we investigated the electrocatalytic oxygen reduction reaction (ORR) activity of vertically aligned, single-layer, carbon-free, and single crystal Pt nanorod arrays utilizing cyclic voltammetry (CV) and rotating-disk electrode (RDE) techniques. A glancing angle deposition (GLAD) technique was used to fabricate 200 nm long Pt nanorods, which corresponds to Pt loading of 0.16 mg/cm2, on glassy carbon (GC) electrode at a glancing angle of 85° as measured from the substrate normal. An electrode comprised of conventional carbon-supported Pt nanoparticles (Pt/C) was also prepared for comparison with the electrocatalytic ORR activity and stability of Pt nanorods. CV results showed that the Pt nanorod electrocatalyst exhibits a more positive oxide reduction peak potential compared to Pt/C, indicating that GLAD Pt nanorods are less oxophilic. In addition, a series of CV cycles in acidic electrolyte revealed that Pt nanorods are significantly more stable against electrochemically-active surface area loss than Pt/C. Moreover, room temperature RDE results demonstrated that GLAD Pt nanorods exhibit higher area-specific ORR activity than Pt/C. The enhanced electrocatalytic ORR activity of Pt nanorods is attributed to their larger crystallite size, single-crystal property, and the dominance of (110) crystal planes on the large surface area nanorods sidewalls, which has been found to be the most active plane for ORR. However, the Pt nanorods showed lower mass specific activity than the Pt/C electrocatalyst due to the large diameter of the Pt nanorods.

Infants' sensitivity to word units in fluent speech was examined by inserting 1 sec pauses either at boundaries between successive words (Coincident versions) or between syllables within words (Noncoincident versions). In Experiment 1, 24 11-month-olds listened significantly longer to the Coincident versions. In Experiment 2, 24 four-and-a-half-and 24 nine-month-olds did not exhibit the preference for the Coincident versions that the 11-month-olds showed. When the stimuli were low-pass filtered in Experiment 3, 24 11-month-olds showed no preference for the Coincident versions, suggesting they rely on more than prosodic cues. New stimulus materials in Experiment 4 indicated that responses by 24 11-month-olds to the Coincident and Noncoindent versions did not depend solely on prior familiarity with the targets. Two groups of 30 11-month-olds tested in Experiment 5 were as sensitive to boundaries for Strong/Weak words as for Weak/Strong words. Taken together, the results suggest that, by 11 months, infants are sensitive to word boundaries in fluent speech, and that this sensitivity depends on more than just prosodic information or prior knowledge of the words.

This paper presents an advanced design and fabrication concept for a solid oxide fuel cell (SOFC). The concept is based on a laminate repeat unit comprised of a thin electrolyte, cermet anode, metallic gas flow fields, and a metallic bipolar plate. The laminate is sintered in a singlestep process in a controlled atmosphere, and the cathode is applied and sintered in situ during the initial heating of the cell (or stack). Observations about the types of cracks that formed in the electrolyte during the sintering process guided the development of the sintering protocol to yield the desired product. Cells with power densities exceeding 250 mW/cm2 have been tested.