White matter hyperintensity (WMH) lesions on brain MRI images are surrogate markers of cerebral small vessel disease. Longitudinal studies examining the association between diabetes and WMH progression have yielded mixed results. Thus, in this study, we investigated the association between HbA1c, a biomarker for the presence and severity of hyperglycemia, and longitudinal WMH change after adjusting for known risk factors for WMH progression. We recruited 64 participants from South Korean memory clinics to undergo brain MRI at the baseline and a 2-year follow-up. We found the following. First, higher HbA1c was associated with greater global WMH volume (WMHV) changes after adjusting for known risk factors (β = 7.7 × 10−4; P = 0.025). Second, the association between baseline WMHV and WMHV progression was only significant at diabetic levels of HbA1c (P < 0.05, when HbA1c >6.51%), and non–apolipoprotein E (APOE) ε4 carriers had a stronger association between HbA1c and WMHV progression (β = −2.59 × 10−3; P = 0.004). Third, associations of WMHV progression with HbA1c were particularly apparent for deep WMHV change (β = 7.17 × 10−4; P < 0.01) compared with periventricular WMHV change and, for frontal (β = 5.00 × 10−4; P < 0.001) and parietal (β = 1.53 × 10−4; P < 0.05) lobes, WMHV change compared with occipital and temporal WMHV change. In conclusion, higher HbA1c levels were associated with greater 2-year WMHV progression, especially in non–APOE ε4 participants or those with diabetic levels of HbA1c. These findings demonstrate that diabetes may potentially exacerbate cerebrovascular and white matter disease. Article Highlights:

Purpose: Two‐dimensional J‐resolved localized and semi‐localized by adiabatic selective refocusing (LASER and semi‐LASER) spectroscopy, named “J‐resolved LASER” and “J‐resolved semi‐LASER”, were introduced to suppress chemical shift artifacts, additional J‐refocused artifactual peaks from spatially dependent J‐coupling evolution, and sensitivity to radiofrequency (RF) field inhomogeneity.Methods: Three pairs of adiabatic pulses were employed for voxel localization in J‐resolved LASER and two pairs in J‐resolved semi‐LASER. The first half of t₁ period was inserted between the last pair of adiabatic pulses, which was proposed in this work to obtain two‐dimensional adiabatic J‐resolved spectra of human brain for the first time. Phantom and human experiments were performed to demonstrate their feasibility and advantages over conventional J‐resolved spectroscopy (JPRESS).Results: Compared to JPRESS, J‐resolved LASER or J‐resolved semi‐LASER exhibited significant suppression of chemical shift artifacts and additional J‐refocused peaks from spatially dependent J‐coupling evolution, and demonstrated insensitivity to the change of RF frequency offset over large bandwidth.Conclusion: Experiments on phantoms and human brains verified the feasibility and strengths of two‐dimensional adiabatic J‐resolved spectroscopy at 3T. This technique is expected to advance the application of in vivo two‐dimensional MR spectroscopy at 3T and higher field strengths for more reliable and accurate quantification of metabolites. Magn Reson Med 71:911–920, 2014. © 2013 Wiley Periodicals, Inc.

Maintaining reliable operation of the bulk power system is a fundamental aspect of grid operation, and focuses on ensuring the system can withstand sudden disturbances or unanticipated failures of system elements such that instability, uncontrolled separation, or cascading failures will not occur. Phasor measurement units (PMUs) provide the capability for enhanced real-time monitoring and control room solutions as well as improved power system analysis in the planning horizon. With over 1,700 PMUs deployed in the North American grid, numerous PMU-based applications have been developed. This paper summarizes synchrophasor-based applications and presents utility synchrophasor experience.