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ContextThe Athletic Training Locations and Services (ATLAS) Annual Report suggested that athletic trainer (AT) employment status differed based on geographic locale. However, the influence of geographic locale and school size on AT employment is unknown.ObjectiveTo determine if differences existed in the odds of having AT services by locale for public and private schools and by student enrollment for public schools.DesignCross-sectional study.SettingPublic and private secondary schools with athletics programs.Patients or Other ParticipantsData from 20 078 US public and private secondary schools were obtained.Main Outcome Measures(s)Data were collected by the ATLAS Project. Athletic trainer employment status, locale (city, suburban, town, or rural) for public and private schools, and school size category (large, moderate, medium, or small) only for public schools were obtained. The employment status of ATs was examined for each category using odds ratios. Logistic regression analysis produced a prediction model.ResultsOf the 19 918 public and private schools with available AT employment status and locale, suburban schools had the highest access to AT services (80.1%) with increased odds compared with rural schools (odds ratio = 3.55 [95% CI = 3.28, 3.85]). Of 15 850 public schools with known AT employment status and student enrollment, large schools had the highest rate of AT services (92.1%) with nearly 18.5 times greater odds (odds ratio = 18.49 [95% CI = 16.20, 21.08]) versus small schools. The logistic model demonstrated that the odds of access to an AT increased by 2.883 times as the school size went up by 1 category.ConclusionsNationally, suburban schools and large public schools had the greatest access to AT services compared with schools that were in more remote areas and with lower student enrollment. These findings elucidate the geographic locales and student enrollment levels with the highest prevalence of AT services.

Previous research from a sample of US secondary schools (n = 10 553) indicated that 67% of schools had access to an athletic trainer (AT; 35% full time [FT], 30% part time [PT], and 2% per diem). However, the population-based statistic in all secondary schools with athletic programs (n = approximately 20 000) is yet to be determined. To determine the level of AT services and employment status in US secondary schools with athletics by National Athletic Trainers' Association district. Cross-sectional study. Public and private secondary schools with athletics. Data from all 20 272 US public and private secondary schools were obtained. Data were collected from September 2015 to April 2018 by phone or e-mail communication with school administrators or ATs and by online surveys of secondary school ATs. Employment categories were school district, school district with teaching, medical or university facility, and independent contractor. Data are presented as total number and percentage of ATs. Descriptive statistics were calculated for FT, PT, and no AT services data for public, private, public + private, and employment type by state and by National Athletic Trainers' Association district. Of the 20 272 secondary schools, 66% (n = 13 473) had access to AT services, while 34% (n = 6799) had no access. Of those schools with AT services, 53% (n = 7119) received FT services, while 47% (n = 6354) received PT services. Public schools (n = 16 076) received 37%, 32%, and 31%, whereas private schools (n = 4196) received 27%, 28%, and 45%, for FT, PT, and no AT services, respectively. Most of the Athletic Training Locations and Services Survey participants (n = 6754, 57%) were employed by a medical or university facility, followed by a school district, school district with teaching, and independent contractor. Combined, 38% of AT employment was via the school district. The percentages of US schools with AT access and FT and PT services were similar to those noted in previous research. One-third of secondary schools had no access to AT services. The majority of AT employment was via medical or university facilities. These data depict the largest and most updated representation of AT services in secondary schools.

The Athletic Training Locations and Services (ATLAS) Annual Report suggests there are differences in athletic trainer (AT) employment status on the basis of geographic locale. However, the influence of geographic locale and the school size on AT employment is undetermined. To describe if differences exist in the odds of having AT services by locale for public and private schools, and by student enrollment for public schools. Cross-sectional study. Public and private secondary schools with athletics programs. Data from 20,078 US public and private secondary schools were obtained. Data were collected by the ATLAS Project. AT employment status, locales (City, Suburban, Town, and Rural) for public and private schools, and school size category (large, moderate, medium, and small) only for public schools were obtained. AT employment status was examined for each category with odds ratios. A prediction model was produced by Logistic Regression Analysis. Of the 19,918 public and private schools with AT employment status and locale, Suburban schools had the highest access to AT services (80.1%) with an increased odds compared with Rural schools (OR = 3.55 [3.28 to 3.850]). Of 15,850 public schools with AT employment status and student enrollment, large schools had the highest rate of having AT services (92.1%) with nearly 18.5 times greater odds (OR = 18.480 [16.197 to 21.083]) versus small schools. The logistic model determined that an odds of having access to AT increases by 2.883 times as the school size goes up by one category. Nationally, Suburban schools and large public schools have the largest access to AT services compared to schools that are in more remote areas and with less student enrollment. These findings elucidate the geographic locales and student enrollment levels where AT services are most prevalent.

Networks of solution-processed nanomaterials are becoming increasingly important across applications in electronics, sensing and energy storage/generation. Although the physical properties of these devices are often completely dominated by network morphology, the network structure itself remains difficult to interrogate. Here, we utilise focused ion beam – scanning electron microscopy nanotomography (FIB-SEM-NT) to quantitatively characterise the morphology of printed nanostructured networks and their devices using nanometre-resolution 3D images. The influence of nanosheet/nanowire size on network structure in printed films of graphene, WS 2 and silver nanosheets (AgNSs), as well as networks of silver nanowires (AgNWs), is investigated. We present a comprehensive toolkit to extract morphological characteristics including network porosity, tortuosity, specific surface area, pore dimensions and nanosheet orientation, which we link to network resistivity. By extending this technique to interrogate the structure and interfaces within printed vertical heterostacks, we demonstrate the potential of this technique for device characterisation and optimisation. The physical properties of devices made of printed nanosheets and nanowires are determined by their intrinsic nanostructured network morphology. Here, the authors use FIB-SEM nanotomography to quantitatively analyze printed nanostructured networks via 3D reconstructions.

Networks of nanowires, nanotubes, and nanosheets are important for many applications in printed electronics. However, the network conductivity and mobility are usually limited by the resistance between the particles, often referred to as the junction resistance. Minimising the junction resistance has proven to be challenging, partly because it is difficult to measure. Here, we develop a simple model for electrical conduction in networks of 1D or 2D nanomaterials that allows us to extract junction and nanoparticle resistances from particle-size-dependent DC network resistivity data. We find junction resistances in porous networks to scale with nanoparticle resistivity and vary from 5 Ω for silver nanosheets to 24 GΩ for WS 2 nanosheets. Moreover, our model allows junction and nanoparticle resistances to be obtained simultaneously from AC impedance spectra of semiconducting nanosheet networks. Through our model, we use the impedance data to directly link the high mobility of aligned networks of electrochemically exfoliated MoS 2 nanosheets (≈ 7 cm 2 V −1 s −1 ) to low junction resistances of ∼2.3 MΩ. Temperature-dependent impedance measurements also allow us to comprehensively investigate transport mechanisms within the network and quantitatively differentiate intra-nanosheet phonon-limited bandlike transport from inter-nanosheet hopping. The electrical properties of nanostructured networks are often dominated by junctions between the particles. Here, Gabett et al. develop transport models and utilise impedance spectroscopy to quantify the factors limiting conduction in these systems.

All-printed transistors consisting of interconnected networks of various types of two-dimensional nanosheets are an important goal in nanoscience. Using electrolytic gating, we demonstrate all-printed, vertically stacked transistors with graphene source, drain, and gate electrodes, a transition metal dichalcogenide channel, and a boron nitride (BN) separator, all formed from nanosheet networks. The BN network contains an ionic liquid within its porous interior that allows electrolytic gating in a solid-like structure. Nanosheet network channels display on:off ratios of up to 600, transconductances exceeding 5 millisiemens, and mobilities of >0.1 square centimeters per volt per second. Unusually, the on-currents scaled with network thickness and volumetric capacitance. In contrast to other devices with comparable mobility, large capacitances, while hindering switching speeds, allow these devices to carry higher currents at relatively low drive voltages.

Solution-processed semiconducting transition metal dichalcogenides are at the centre of an ever-increasing research effort in printed (opto)electronics. However, device performance is limited by structural defects resulting from the exfoliation process and poor inter-flake electronic connectivity. Here, we report a new molecular strategy to boost the electrical performance of transition metal dichalcogenide-based devices via the use of dithiolated conjugated molecules, to simultaneously heal sulfur vacancies in solution-processed transition metal disulfides and covalently bridge adjacent flakes, thereby promoting percolation pathways for the charge transport. We achieve a reproducible increase by one order of magnitude in field-effect mobility ( µ FE ), current ratio ( I ON / I OFF ) and switching time ( τ S ) for liquid-gated transistors, reaching 10 −2  cm 2  V −1  s −1 , 10 4 and 18 ms, respectively. Our functionalization strategy is a universal route to simultaneously enhance the electronic connectivity in transition metal disulfide networks and tailor on demand their physicochemical properties according to the envisioned applications. A defect-engineering strategy exploiting dithiolated molecules enables the formation of covalently interconnected networks based on solution-processed transition metal disulfides, leading to devices with enhanced electrical performance and improved characteristics.

Solution-processed networks of 2D nanosheets are promising for a range of applications in the field of printed electronics. However, the electrical performance of these networks — represented, for example, by the mobility — is almost always inferior to that of the individual nanosheets. In this Review, we highlight the central role that the inter-sheet junctions play in determining the electrical characteristics of such networks. After briefly reviewing ink formulation and printing methods, we use a selection of electronic applications as examples to demonstrate the dependence of network conductivity on network morphology. We show the network morphology to be heavily influenced by the deposition method, the post-treatment regime and the nanosheet properties. In turn, the morphology of the network fundamentally determines the properties of the inter-sheet junctions, which, ultimately, control the electrical performance of the network. We use reported electrical data to show that three main conduction regimes exist: the network conductivity can be limited by the junctions, by a combination of junction and material properties or, very rarely, by the material properties. Using a meta-analysis of published data, we propose simple models relating network conductivity and mobility to the junction resistance. Solution-processed networks of 2D materials are promising for applications in printed electronics. This Review examines how these networks are often electrically limited by the junctions between nanosheets, a phenomenon rarely reported and poorly understood, and surveys the macroscopic electrical properties of printed 2D networks, with a focus on inter-sheet junctions.

Cancer-associated fibroblasts (CAFs) are a prominent stromal cell type in solid tumors and molecules secreted by CAFs play an important role in tumor progression and metastasis. CAFs coexist as heterogeneous populations with potentially different biological functions. Although CAFs are a major component of the breast cancer stroma, molecular and phenotypic heterogeneity of CAFs in breast cancer is poorly understood. In this study, we investigated CAF heterogeneity in triple-negative breast cancer (TNBC) using a syngeneic mouse model, BALB/c-derived 4T1 mammary tumors. Using single-cell RNA sequencing (scRNA-seq), we identified six CAF subpopulations in 4T1 tumors including: 1) myofibroblastic CAFs, enriched for α-smooth muscle actin and several other contractile proteins; 2) ‘inflammatory’ CAFs with elevated expression of inflammatory cytokines; and 3) a CAF subpopulation expressing major histocompatibility complex (MHC) class II proteins that are generally expressed in antigen-presenting cells. Comparison of 4T1-derived CAFs to CAFs from pancreatic cancer revealed that these three CAF subpopulations exist in both tumor types. Interestingly, cells with inflammatory and MHC class II-expressing CAF profiles were also detected in normal breast/pancreas tissue, suggesting that these phenotypes are not tumor microenvironment-induced. This work enhances our understanding of CAF heterogeneity, and specifically targeting these CAF subpopulations could be an effective therapeutic approach for treating highly aggressive TNBCs.

Uric acid (UA) is known to activate the NLRP3 (Nacht, leucine-rich repeat and pyrin domain containing protein 3) inflammasome. When activated, the NLRP3 (also known as NALP3) inflammasome leads to the production of IL-18 and IL-1β. In this cohort of subjects with knee osteoarthritis (OA), synovial fluid uric acid was strongly correlated with synovial fluid IL-18 and IL-1β. Synovial fluid uric acid and IL-18 were strongly and positively associated with OA severity as measured by both radiograph and bone scintigraphy, and synovial fluid IL-1β was associated with OA severity but only by radiograph. Furthermore, synovial fluid IL-18 was associated with a 3-y change in OA severity, on the basis of the radiograph. We conclude that synovial fluid uric acid is a marker of knee OA severity. The correlation of synovial fluid uric acid with the two cytokines (IL-18 and IL-1β) known to be produced by uric acid-activated inflammasomes and the association of synovial fluid IL-18 with OA progression, lend strong support to the potential involvement of the innate immune system in OA pathology and OA progression.