We experimentally measured the self-healing of the spatially inhomogeneous states of polarization of radial and azimuthal polarized vector Bessel beams. Radial and azimuthal polarized vector Bessel beams were generated via a digital version of Durnin's method, using a spatial light modulator in concert with a liquid crystal q-plate. As a proof of principle, their intensities and spatially inhomogeneous states of polarization were measured using Stokes polarimetry as they propagated through two disparate obstructions. It was found, similar to their intensities, the spatially inhomogeneous states of polarization of a radial and azimuthal polarized vector Bessel beams self-heal. Similar to scalar Bessel beams, the self-healing of vector Bessel beams can be understood via geometric optics, i.e., the interference of the unobstructed conical rays in the shadow region of the obstruction. The self-healing of vector Bessel beams may have applications in, for example, optical trapping.

IMPORTANCEThe Affordable Care Act expanded access to Medicaid coverage in 2014 for individuals living in participating states. Whether expanded coverage was associated with increases in the use of outpatient surgical care, particularly among underserved populations, remains unknown.OBJECTIVE To evaluate the association between state participation in the Affordable Care Act Medicaid expansion reform and the use of outpatient surgical care. DESIGN, SETTING, AND PARTICIPANTSThis case-control study used a quasi-experimental difference-in-differences design to compare the use of outpatient surgical care at the facility and state levels by patient demographic characteristics and payer categories (Medicaid, private insurance, and no insurance). Data from 2013 (before Medicaid expansion reform) and 2015 (after Medicaid expansion reform) were obtained from the State Ambulatory Surgery and Services Database of the Healthcare Cost and Utilization Project. The absolute and mean numbers of procedures performed at outpatient surgical centers in 2 states (Michigan and New York) that participated in Medicaid expansion (expansion states) were compared with those performed at outpatient surgical centers in 2 states (Florida and North Carolina) that did not participate in Medicaid expansion (nonexpansion states). The population-based sample included 207 176 patients aged 18 to 64 years who received 4 common outpatient procedures (laparoscopic cholecystectomy, breast lumpectomy, open inguinal hernia repair, and laparoscopic inguinal hernia repair). Data were analyzed from May 19 to August 25, 2019.INTERVENTIONS State variation in the adoption of Medicaid expansion before and after expansion reform was implemented through the Affordable Care Act. MAIN OUTCOMES AND MEASURESChanges in the mean number of procedures performed at the facility level before and after Medicaid expansion reform in states with and without expanded Medicaid coverage.RESULTS A total of 207 176 patients (106 395 women [51.35%] and 100 781 men [48.65%]; mean [SD] age, 45.7 [12.4] years) were included in the sample. Overall, 116 752 procedures were performed in Medicaid expansion states and 90 424 procedures in nonexpansion states. A 9.8% increase (95% CI, 0.4%-20.0%; P = .04) in cholecystectomies, a 26.1% increase (95% CI, 9.8%-44.7%; P = .001) in lumpectomies, and a 16.3% increase (95% CI, 2.9%-31.5%; P = .02) in laparoscopic inguinal hernia repairs were observed at the facility level in expansion states compared with nonexpansion states. Among patients with Medicaid coverage, the mean number of procedures performed in all 4 procedure categories increased between 60.5% (95% CI, 24.7%-106.6%; P < .001) and 79.2% (95% CI, 53.5%-109.2%; P < .001) at the facility level. The increases in the number of Medicaid patients who received treatment exceeded the reductions in the number of uninsured patients who received treatment with laparoscopic cholecystectomy, open inguinal hernia repair, and laparoscopic inguinal hernia repairs in expansion states compared with nonexpan...

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