Association between Blood Pressure and Renal Progression in Korean Adults with Normal Renal Function.

BACKGROUND: Although hypertension (HTN) is a well-established major risk factor for renal progression in patients with chronic kidney disease (CKD), few studies investigating its role in renal deterioration in the general population with normal renal function (NRF) have been published. Here, we analyzed the correlation between blood pressure (BP) and impaired renal function (IRF) in Korean adults with NRF. METHODS: Data for the study were collected from the national health screening database of the Korean National Health Insurance Service. Patients whose baseline estimated glomerular filtration rate (eGFR) was less than 60 mL/min/1.73 m² or whose baseline urinalysis showed evidence of proteinuria were excluded. IRF was defined as an eGFR below 60 mL/min/1.73 m². We performed follow up for eGFR for 6 years from 2009 to 2015 and investigated IRF incidence according to baseline BP status. We categorized our study population into two groups of IRF and NRF according to eGFR level in 2015. RESULTS: During 6 years of follow-up examinations, IRF developed in 161,044 (2.86%) of 5,638,320 subjects. The IRF group was largely older, and the incidence was higher in females and patients with low income, HTN, diabetes mellitus, dyslipidemia, and obesity compared with the NRF group. Subjects whose systolic BP was more than 120 mmHg or whose diastolic BP was more than 70 mmHg had an increased risk of developing IRF compared with subjects with lower BP (odds ratio [OR], 1.037; 95% confidence interval [CI], 1.014-1.061 vs. OR, 1.021; 95% CI, 1.004-1.038). CONCLUSION: BP played a major role in renal progression in the general population with NRF. Strict BP control may help prevent CKD in the general population.

Silicon nitride optical phased array based on a grating antenna enabling wavelength-tuned beam steering.

An optical phased array (OPA) in silicon nitride (SiN) is conspicuously highlighted as a vital alternative to its counterpart in silicon. However, a limited number of studies have been conducted on this array in terms of wavelength-tuned beam steering. A SiN OPA has been proposed and implemented with a grating antenna that incorporated an array of shallow-etched waveguides, rendering wavelength-tuned beam steering along the longitudinal direction. To accomplish a superior directionality on a wavelength-tuned beam steering, the spectral beam emission characteristics of the antenna have been explored from the viewpoint of a planar structure that entails a buried oxide (BOX), a SiN waveguide core, and an upper cladding. Two OPA devices having substantially different thicknesses of the resonant cavities, established by combining the BOX and SiN core, were considered theoretically and experimentally to scrutinize the spectral emission characteristics of the antenna on beam steering. Both of the fabricated OPA devices steered light by an angle of 7.4° along the longitudinal direction for a wavelength ranging from 1530 to 1630 nm, while they maintained a divergence angle of 0.2°×0.6° in the longitudinal and lateral directions. Meanwhile, the OPA fabricated on a substantially thick BOX layer featured a limited steering performance to attain a stabilized response over a broad spectral region. We examined the influence of the cavity thickness on the spectral response of the antenna in terms of optical thickness. Based on the two antenna characteristics, it was confirmed that the grating antenna emitted the beam with a higher efficiency when the optical thickness of the cavity corresponded to odd integer multiples of the quarter wavelength. This work is a considerable strategy for designing a stabilized SiN OPA over a desired spectral region.