ABSTRACT
Two-dimensional transition metal nitrides offer intriguing possibilities for achieving novel electronic and mechanical functionality owing to their distinctive and tunable bonding characteristics compared to other 2D materials. We demonstrate here the enabling effects of strong bonding on the morphology and functionality of 2D tungsten nitrides. The employed bottom-up synthesis experienced a unique substrate stabilization effect beyond van-der-Waals epitaxy that favored W5N6 over lower metal nitrides. Comprehensive structural and electronic characterization reveals that monolayer W5N6 can be synthesized at large scale and shows semimetallic behavior with an intriguing indirect band structure. Moreover, the material exhibits exceptional resilience against mechanical damage and chemical reactions. Leveraging these electronic properties and robustness, we demonstrate the application of W5N6 as atomic-scale dry etch stops that allow the integration of high-performance 2D materials contacts. These findings highlight the potential of 2D transition metal nitrides for realizing advanced electronic devices and functional interfaces.
ABSTRACT
BACKGROUND: The 2013 ACC/AHA Guideline on the Treatment of Blood Cholesterol to Reduce Atherosclerotic Cardiovascular Risk in Adults emphasizes evidence-based treatment with moderate- to high-dose statins for patients at high risk for atherosclerotic cardiovascular disease (ASCVD). Whether this new guideline influenced patterns of treatment 1 year after its dissemination is unknown. OBJECTIVE: To compare patterns of lipid-lowering treatment before and 1 year after the release of the 2013 cholesterol guideline in 2 high-risk groups: patients with ASCVD and patients with diabetes mellitus. METHODS: Using pharmacy and medical claims from a large U.S. health insurance organization, 610,535 patients with ASCVD (n = 301,440) or diabetes mellitus (n = 309,095) were identified, and statin treatment rates and statin intensity were examined before and 1 year after the dissemination of the 2013 cholesterol guideline. A standardized difference of at least 10% was required to declare the effect size meaningful. RESULTS: Overall, there was no change in statin treatment rates for patients with ASCVD (48.0% before guideline vs. 47.3% after, standardized difference 1.4%) or diabetes (50% vs. 51.5% after, standardized difference 2.4%). Statin initiation rates among patients not on statins before the 2013 guideline were 10.1% in patients with ASCVD and 14.3% in patients with diabetes, but these gains were offset by 13.0% and 12.2% statin discontinuation rates among ASCVD and diabetes patients, respectively. Among patients taking statins 1 year after the guideline was issued, 80% of patients with ASCVD and aged ≤ 75 years were not on guideline-recommended high-intensity statin therapy, whereas most patients with ASCVD and aged > 75 years or patients with diabetes were on moderate- or high-intensity statin treatment. CONCLUSIONS: One year after dissemination of the 2013 cholesterol guideline, overall treatment rates with statins among patients with ASCVD and diabetes did not change appreciably, and many patients remained either untreated or undertreated. DISCLOSURES: No outside funding supported this research. Chan is supported by grants from the National Heart Lung and Blood Institute (1R01HL123980 and K23HL102224). Tran, Stockl, Lew, and Solow are employed by Optum. Kao and Caglar were employed by Optum when this study was conducted. Chan serves as an advisor and consultant to OptumRx but received no compensation for work on this manuscript. Stockl is also employed by the Journal of Managed Care & Specialty Pharmacy. Spertus reports personal fees from United Healthcare and grants from Lilly, outside of the submitted work. None of the authors have any other financial conflicts of interest to report. Tran and Chan supervised this study, had full access to all of the data in the study, and take responsibility for the integrity of the data and the accuracy of the data analysis. Study design and concept were contributed by Tran and Chan. Tran and Kao collected the data, with analysis and interpretation performed by all the authors. Statistical analysis was performed by Caglar and Kao, and Tran and Chan drafted the manuscript. All authors were involved in the critical revision of the manuscript.
