Natural killer (NK) cells belong to the innate immune system; they can control virus infections and developing tumors by cytotoxicity and producing inflammatory cytokines. Most studies of mouse NK cells, however, have focused on conventional NK (cNK) cells in the spleen. Recently, we described two populations of liver NK cells, tissue-resident NK (trNK) cells and those resembling splenic cNK cells. However, their lineage relationship was unclear; trNK cells could be developing cNK cells, related to thymic NK cells, or a lineage distinct from both cNK and thymic NK cells. Herein we used detailed transcriptomic, flow cytometric, and functional analysis and transcription factor-deficient mice to determine that liver trNK cells form a distinct lineage from cNK and thymic NK cells. Taken together with analysis of trNK cells in other tissues, there are at least four distinct lineages of NK cells: cNK, thymic, liver (and skin) trNK, and uterine trNK cells.DOI: http://dx.doi.org/10.7554/eLife.01659.001

An appealing avenue for organic spintronics lies in direct coherent control of the spin population by means of pulsed electron spin resonance techniques. Whereas previous work has focused on the electrical detection of coherent spin dynamics, we demonstrate here the equivalence of an all-optical approach, allowing us to explore the influence of materials chemistry on the spin dynamics. We show that deuteration of the conjugated polymer side groups weakens the local hyperfine fields experienced by electron-hole pairs, thereby lowering the threshold for the resonant radiation intensity at which coherent coupling and spin beating occur. The technique is exquisitively sensitive to previously obscured material properties and offers a route to quantifying and tuning hyperfine fields in organic semiconductors.

Summary: Plastic surgeons have the unique perspective of working with all types of patients and care teams from almost all specialties in surgery and medicine, which creates unique challenges in times of distress. As the initial epicenter of coronavirus disease 2019 cases in the United States, the University of Washington program was required to rapidly develop strategies to deal with the escalating crisis. All aspects of the program were affected, including the need to triage the urgency of plastic surgery care, safe staffing of plastic surgery teams, and the role of plastic surgery in the greater hospital community. In addition, as a residency training program, limiting the impact of resident education and maintaining a sense of community and connection among members of the program developed into important considerations. The authors hope that the narrative of their experience will provide insight into the decisions made in the University of Washington health care system but also remind others that they are not alone in dealing with the challenges of this pandemic.