Correlation between short- and mid-term hemoglobin A1c and glycemic control determined by continuous glucose monitoring.

BACKGROUND: Glucose monitoring is vital for glycemic control in patients with diabetes mellitus (DM). Continuous glucose monitoring (CGM) measures whole-day glucose levels. Hemoglobin A1c (HbA1c) is a vital outcome predictor in patients with DM. METHODS: This study investigated the relationship between HbA1c and CGM, which remained unclear hitherto. Data of patients with DM (n = 91) who received CGM and HbA1c testing (1-3 months before and after CGM) were retrospectively analyzed. Diurnal and nocturnal glucose, highest CGM data (10%, 25%, and 50%), mean amplitude of glycemic excursions (MAGE), percent coefficient of variation (%CV), and continuous overlapping net glycemic action were compared with HbA1c values before and after CGM. RESULTS: The CGM results were significantly correlated with HbA1c values measured 1 (r = 0.69) and 2 (r = 0.39) months after CGM and 1 month (r = 0.35) before CGM. However, glucose levels recorded in CGM did not correlate with the HbA1c values 3 months after and 2-3 months before CGM. MAGE and %CV were strongly correlated with HbA1c values 1 and 2 months after CGM, respectively. Diurnal blood glucose levels were significantly correlated with HbA1c values 1-2 months before and 1 month after CGM. The nocturnal blood glucose levels were significantly correlated with HbA1c values 1-3 months before and 1-2 months after CGM. CONCLUSIONS: CGM can predict HbA1c values within 1 month after CGM in patients with DM.

A longitudinal, cross-lagged panel analysis of loneliness and depression among community-based older adults.

In the present study, we intended to examine the temporal association between loneliness and depression among community-based older adults. We analyzed data on 3,920 persons with a mean age of 67.6 years at baseline from the Taiwan Longitudinal Study on Aging. Structural equation modeling was used to investigate the temporal association between loneliness and depression over a period of 14 years. The results showed that the temporal association between loneliness and depression was bidirectional but stronger and more robust for depression as the initial symptom. Loneliness at Time 1 and 3, respectively, significantly predicted depression at Time 2 and 4. Depression at each time point had a significant effect on subsequent loneliness, even considering covariates. Future prevention programs for older adults with depression should also target at dealing with their loneliness, and vice versa. This study also highlights the need to assess and to manage the two symptoms simultaneously.

Demonstration of Enhanced Optical Pressure on a Structured Surface.

The interaction of electromagnetic waves with condensed matter and the resultant force is fundamental in the physical sciences. The maximum pressure on a planar surface is understood to be twice the incident wave power density normalized by the background velocity. We demonstrate for the first time that this pressure can be exceeded by a substantial factor by structuring a surface. Experimental results for direct optomechanical deflection of a nanostructured gold film on a silicon nitride membrane illuminated by a laser beam are shown to significantly exceed those for the planar surface. This enhanced pressure can be understood as being associated with an asymmetric optical cavity array realized in the membrane film. The possible enhancement depends on the material properties and the geometrical parameters of the structured material. Such control and increase of optical pressure with nanostructured material should impact applications across the physical sciences.

Bending loss of terahertz pipe waveguides.

We present an experimental study on the bending loss of terahertz (THz) pipe waveguide. Bending loss of pipe waveguides is investigated for various frequencies, polarizations, core diameters, cladding thicknesses, and cladding materials. Our results indicate that the pipe waveguides with lower guiding loss suffer lower bending loss due to stronger mode confinement. The unexpected low bending loss in the investigated simple leaky waveguide structure promises variety of flexible applications.

Low-index terahertz pipe waveguides.

We propose and demonstrate a simple leaky structure for terahertz (THz) waveguiding. Different from previously reported air-core THz waveguides, in which a high-reflection-coated cladding layer is designed, the proposed structure here is a simple pipe with a large air core and a thin dielectric layer with uniform but low index. Using commercially available Teflon air pipes, we experimentally confirm that THz waves can be successfully guided in the central air core of 3-m-long pipes with excellent mode qualities, high coupling efficiencies, low attenuation constants, and controllable passband width.