No abstract

The control of tobacco use in adolescents is a critical public health issue that has long been studied, yet has received less attention than adult smoking cessation. Shared decision making (SDM) is a method that highlights a patient’s preference-based medical decision. This study aimed to investigate the effects of a novel SDM-integrated cessation model and early intervention on the control of tobacco use in adolescents. The SDM-integrated model provides psychological support and motivational enhancement by involving the participants in making decisions and plans through the three-talk model of the SDM principle. The primary outcome shows positive effects by both increasing the cessation rate (a 25% point abstinence rate at 3 month follow up) and decreasing the number of cigarettes smoked per day (60% of the participants at 3 month follow up) among 20 senior high school participants (mean age, 17.5 years; 95% male). The results also show that the model can achieve the goal of SDM and optimal informed decision making, based on the positive SURE test and the satisfaction survey regarding the cessation model. The SDM cessation model can be further applied to different fields of adolescent substance cessation, yielding beneficial effects regarding reducing potential health hazards. The dissemination of the model may help more adolescent smokers to cease smoking worldwide.

In this work, we demonstrated the thermal analysis of different flip-chip bonding designs for high power GaN HEMT developed for power electronics applications, such as power converters or photonic driver applications, with large gate periphery and chip size, as well as an Au metal heat-spreading layer deposited on top of a planarized dielectric/passivation layer above the active region. The Au bump patterns can be designed with high flexibility to provide more efficient heat dissipation from the large GaN HEMT chips to an AlN package substrate heat sink with no constraint in the alignment between the HEMT cells and the thermal conduction bumps. Steady-state thermal simulations were conducted to study the channel temperatures of GaN HEMTs with various Au bump patterns at different levels of current and voltage loadings, and the results were compared with the conventional face-up GaN die bonding on an AlN package substrate. The simulations were started from a single finger isolated HEMT cell and then extended to multiple fingers HEMT cells (total gate width > 40 mm) to investigate the “thermal cross-talk” effect from neighboring devices. Thermal analysis of the GaN HEMT under pulse operation was also performed to better reflect the actual conditions in power conversion or pulsed laser driver applications. Our analysis provides a combinational assessment of power GaN HEMT dies under a working condition (e.g., 1MHz, 25% duty cycle) with different flip chip packaging schemes. The analysis indicated that the channel temperature rise (∆T) of a HEMT cell in operation can be reduced by 44~46% by changing from face-up die bonding to a flip-chip bonding scheme with an optimized bump pattern design.