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SummaryProtein kinase C (PKC) is a heterogeneous family of serine ⁄ ⁄ threonine protein kinases that have different biological effects in normal and neoplastic melanocytes (MCs). To explore the mechanism behind their differential response to PKC activation, we analyzed the expression profile of all nine PKC isoforms in normal human MCs, HPV16 E6 ⁄ ⁄ E7 immortalized MCs, and a panel of melanoma cell lines. We found reduced PKCb and increased PKCf and PKCi expression at both the protein and mRNA levels in immortalized MCs and melanoma lines. We focused on PKCb as it has been functionally linked to melanin production and oxidative stress response. Re-expression of PKCb in melanoma cells inhibited colony formation in soft agar, indicating that PKCb loss in melanoma is important for melanoma growth. PKCbII, but not PKCbI, was localized to the mitochondria, and inhibition of PKCb significantly reduced UV-induced reactive oxygen species (ROS) in MCs with high PKCb expression. Thus alterations in PKCb expression in melanoma contribute to their neoplastic phenotype, possibly by reducing oxidative stress, and may constitute a selective therapeutic target.

The crystal structure of the α polymorph of nylon 4 has been determined from the x‐ray diffraction patterns of uniaxially oriented monofilaments. In general the crystal structure of α nylon 4 is similar to that of α nylon 6. The unit cell is monoclinic with the following dimensions: a = 9.29 ± 0.05 A., b = 12.24 ± 0.05 A., c = 7.97 ± 0.05 A., and β = 114.5 ± 1.0°. There are eight monomeric units in the unit cell. The theoretical density is 1.37 g./cc. and the observed density 1.25 g./cc. The space group is P21. The nylon 4 chains are of the extended planar zigzag type, with the plane of the zigzag approximately parallel to the a axis of the unit cell. Along the a axis, every other chain is inverted—an antiparallel arrangement of chains—thus permitting complete hydrogen bonding and the formation of sheets of nylon 4 chains. Along the c axis of the unit cell, the second sheet is displaced by3/10 of the b axis, thus leading to a staggered arrangement of sheets. The sheets are held in place by van der Waals forces.

Limitations of the study include the observational design, the small number of participants from a single center, and the inability to adjust for confounding characteristics; hence, results may not generalize to other settings with different demographic characteristics. The period of risk for infection was slightly later for the vaccinated cohort than the unvaccinated cohort. However, the study encompassed a sustained period of high community transmission. 2 Black HCWs constituted a higher percentage of the SARS-CoV-2-positive unvaccinated cohort, although these data were not statistically significant. Finally, these findings address primarily the short-term effects of a single dose of mRNA-1273 vaccine.

Among 3926 healthcare personnel in a multisite healthcare system, the minimal population prevalence of coronavirus disease 2019 (COVID-19) was 4.4% (bootstrap 95% confidence interval [CI], 3.7%–5.0%), and the infection fatality rate was 0.6% (bootstrap 95% CI, 0.0%–1.7%). Rates reflected both local community prevalence and hospital exposures but not specifically exposure on COVID-19 units.

In addition to the α polymorph, two crystalline forms of nylon 4, the β and δ polymorphs, have been observed and studied. The β polymorph of nylon 4, which has not been found in a pure condition, appears to be similar to the β polymorph of nylon 6. The extended planar zigzag conformation of chains, found in the α polymorph, is present also in the β polymorph. Three models have been proposed to explain the observed data. In model 1, the staggered shear of van der Waals bonded sheets found in the α polymorph is abandoned; in model 2, the sheets are displaced by 1/2 the b axis, and in model 3 the chains are arranged in a parallel array. The β polymorph is converted to the α form in air upon heating for 11 min. at 227°C. and upon immersion in water for 2 hr. Models 1 and 2 would be converted to the α polymorph by a slippage of the van der Waals bonded sheets while the conversion from model 3 would involve a rupture of hydrogen bonds, a rotation of the chains through 90°, and the reformation of hydrogen bonds. The δ polymorph is formed by rapidly quenching extruded nylon 4 against chilled rolls. It is a metastable form which has only been observed in an unoriented condition. Upon orientation it is completely converted to the α polymorph. In addition to this, its conversion to the α form occurs under conditions similar to the β–α transition. The observed diffraction pattern can be indexed on the basis of a hexagonal packing of chains. High‐temperature x‐ray diffraction studies of the α polymorph suggest that the δ form, or a structure similar to it, is the high‐temperature form of nylon 4.

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Objective Reducing risk of coronavirus disease 2019 (COVID-19) infection among healthcare personnel requires a robust occupational health response involving multiple disciplines. We describe a flexible informatics solution to enable such coordination, and we make it available as open-source software. Materials and Methods We developed a stand-alone application that integrates data from several sources, including electronic health record data and data captured outside the electronic health record. Results The application facilitates workflows from different hospital departments, including Occupational Health and Infection Control, and has been used extensively. As of June 2020, 4629 employees and 7768 patients and have been added for tracking by the application, and the application has been accessed over 46 000 times. Discussion Data captured by the application provides both a historical and real-time view into the operational impact of COVID-19 within the hospital, enabling aggregate and patient-level reporting to support identification of new cases, contact tracing, outbreak investigations, and employee workforce management. Conclusions We have developed an open-source application that facilitates communication and workflow across multiple disciplines to manage hospital employees impacted by the COVID-19 pandemic.