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This work investigates the off-state leakage characteristics of AlN/GaN/AlGaN high electron mobility transistors (HEMTs) on Si substrate with varying mesa depths and uncovers the existence of a parasitic channel associated with the AlGaN back barrier. Significant differences in off-state leakage up to three orders of magnitude were observed between devices fabricated using different mesa depths. The electrical properties of AlN/GaN/AlGaN HEMTs were measured, and it was found that there is a N-type parasitic channel in the unintentionally doped AlGaN back-barrier. Analysis of the isolation test structure, which retains this parasitic channel, reveals a buffer leakage of 12.8 mA/mm and a sheet resistance of 7739.1 Ω/sq, as a result of the parasitic channel. The depletion electric field strength of the parasitic channel is 3.2 × 105 V/cm. Temperature-dependent I–V curves obtained from the isolation area affirm that the primary leakage mechanism is two-dimensional variable range hopping along the sidewall. As the isolation distance extends from 3 to 5 μm, the slope of the fitting line decreases from −53.14 to −126.11 due to increased resistance. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the effects of pharmaceutical care interventions on blood pressure (BP) and medication adherence of patients with primary hypertension in China. A total of 60 patients with primary hypertension were enrolled in the trial for a 12-month period. Participants were randomized to either control group or intervention group in a 1:1 ratio. During the follow-up period, patients in the control group were given regular medi-care, while patients in the intervention group accepted pharmaceutical care. The dates of baseline demographics, medication lists, measurement of medication adherence, and BP values were collected. Statistical analyses were conducted using t-test or χχ2 test. After 12 months follow-up, 24-h BP was significantly decreased by 9.75 mmHg (7.1%) for systolic blood pressure (SBP) and 5.88 mmHg (6.6%) for diastolic blood pressure (DBP) in the intervention group ( p < 0.05) compared with their initial visit, while there was no significant change in the control group ( p > 0.05). The intervention group demonstrated a higher percentage of patients with high adherence (72.41%) at 12 months, whereas the control group hardly had changes in medication compliance. In conclusion, the results indicate that pharmaceutical care intervention might contribute to better BP control of primary hypertension, and could enhance medication compliance of patients. [ABSTRACT FROM AUTHOR]