The insulator in MIS structure is silicon nitride films (SiN), which were deposited by either low pressure chemical vapor deposition (LPCVD) or plasma enhanced chemical vapor deposition (PECVD) processes. Phosphorus or boron ions were implanted into dielectric layer in order to introduce impurity energy levels into the band gap of SiN. The relaxation processes of the injected charges in SiN were changed due to the ion implantation, which selleck chemicals llc led to the change in relaxation time of the trapped charges. In our experiments, the space charges were introduced by stressing the sample electrically

with dc biasing. The effects of implantation process on charge accumulation and dissipation in the dielectric are studied by capacitance-voltage (C-V) measurement qualitatively and quantitatively. The experimental results show that the charging and discharging behavior of the ion implanted silicon nitride films deposited by LPCVD is quite different from the one deposited by PECVD. The charge accumulation in the dielectric film can be reduced by ion implantation with proper dielectric deposition method. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3147862]“
“Background: Thoracic impedance (TI) influences the success of external cardioversion (ECV) or defibrillation because current intensity traversing GDC-0994 the

heart is inversely related to TI. Experimental data suggest selleck chemical that TI decreases after multiple shocks. We undertook a clinical study to determine changes of TI values in patients with atrial fibrillation or flutter requiring ECV.

Methods: We enrolled 222 consecutive patients (age 73 +/- 11 years; males 67%; body weight 75 +/- 13 kg) who underwent ECV between January 2004 and February 2007. Biphasic shocks were delivered through adhesive pads placed in the anteroposterior position.

The initial energy was set at 1 J/kg, with progressive increases up to a maximum of 180 J in case of failure. In the last 39 elective patients, plasma concentration of interleukin-6 (IL-6) and tumor necrosis factor (TNF)-alpha were determined before and 6 hours after ECV.

Results: Sinus rhythm was restored in 202 patients (91.0%). Of these, 155 (69.8%) required more than one shock (on average, 2.5 +/- 1.5 shocks/patient). Final values of energy and peak current intensity were 136 +/- 47 J and 50 +/- 14 A, respectively. TI decreased significantly by 6.2% from baseline after >= 2 shocks (P < 0.001). The absolute reduction was correlated with baseline TI, number of delivered shocks, and hemoglobin oxygen saturation. IL-6 and TNF-alpha increased with ECV (P < 0.001 and P = 0.014, respectively).

Conclusions: TI decreases significantly after multiple shocks, possibly by activation of acute inflammation.

(PACE 2009; 32:371-377).