The Frontline Health Care Workers in Schools: Health Equity, the Distribution of School Nurses, and Student Access.

The extent to which observed disparities in access to primary pediatric care are mirrored in student access to school nursing services is unknown. Using school employment records, we linked 1,346 nurses to school districts serving 1,141,495 students in Washington state. The percentage of students who are Black is negatively associated with the student-to-nurse ratio, while the percentage of students eligible for free-or-reduced-price lunch is positively associated, and relative to urban districts, rural districts have higher student-to-nurse ratios. Disparities in access to school nursing services mirror access gaps for pediatric care along socioeconomic status and geography. The increased number of nurses working in districts with more racial/ethnic minority students may play a protective role and ameliorate access gaps observed in pediatric primary care. States can likely use existing employment and licensing data to understand where school nurses work and therefore guide resource allocation decisions.

Repair of a calvarial defect with biofactor and stem cell-embedded polyethylene glycol scaffold.

OBJECTIVE: Segmental bony defects resulting from congenital facial anomalies, facial trauma, infection, or oncologic surgical resection represent a common and significant clinical problem. Currently, these defects are reconstructed with autologous or allogeneic bone grafts or prosthetic devices. These options are limited by bone supply for grafting, donor site morbidity, risk of infection, and extrusion. This study investigated the in vivo osteogenic capability of polyethylene glycol-diacrylate (PEG-DA) and a protease-sensitive PEG matrix metalloproteinases (PEG-MMP), photoencapsulated with mesenchymal stem cells (MSCs) and bone morphogenetic protein (BMP)-2, in healing a critical-size rat calvarial defect. METHODS: Both PEG-DA and PEG-MMP scaffolds photoencapsulated with rat MSCs (rMSCs) and/or BMP-2 were implanted into a critical-size defect. Microcomputed-tomographic (micro-CT) analysis was completed 1, 4, and 8 weeks after implantation. Bone growth was histologically evaluated. The micro-CT data were analyzed using ASPIProVM software to calculate the percentage of closure of cranial defects. RESULTS: Both PEG-MMP and PEG-MMP + BMP2 showed significantly enhanced bone compared with controls. Polyethylene glycol-diacrylate seemed to inhibit bone growth regardless of biofactor and rMSCs. The addition of rMSCs did not enhance bone regeneration. CONCLUSION: Polyethylene glycol sensitive to proteolysis significantly improved bone repair in a critical-size calvarial defect.

Electronic confinement and coherence in patterned epitaxial graphene.

Ultrathin epitaxial graphite was grown on single-crystal silicon carbide by vacuum graphitization. The material can be patterned using standard nanolithography methods. The transport properties, which are closely related to those of carbon nanotubes, are dominated by the single epitaxial graphene layer at the silicon carbide interface and reveal the Dirac nature of the charge carriers. Patterned structures show quantum confinement of electrons and phase coherence lengths beyond 1 micrometer at 4 kelvin, with mobilities exceeding 2.5 square meters per volt-second. All-graphene electronically coherent devices and device architectures are envisaged.