Out-of-hospital cardiac arrest: incidence, process of care, and outcomes in an urban city, Korea.

OBJECTIVE: We aimed to determine the incidence, processes of care, and outcomes in out-of-hospital cardiac arrests (OHCA) in Ansan, South Korea. METHODS: From the Ansan Fire Department's (1-1-9 emergency call number) Emergency Medical Services (EMS) database, we obtained a list of adult cardiac arrest cases occurring between January 2008 and December 2011. We excluded cases with obvious non-cardiac causes, such as trauma, drowning, hanging, and asphyxia. We matched the EMS data with in-hospital care and outcome data. We analyzed basic demographic variables (age and gender), the time and place of incidence, witnesses, bystander cardiopulmonary resuscitation (CPR), major time variables, CPR instructions during transport, initial cardiac rhythm at the scene, and automated defibrillator use. RESULTS: The overall incidence of OHCA in Ansan was 33.1/100,000 persons per year. Out of 778 adult OHCAs in our study population, bystander CPR was provided in 103 cases (13.2%). Of the 517 OHCAs whose initial rhythms were confirmed, 85 (16.4%) showed shockable rhythms, but only 23 (27.1%) received defibrillation at the scene or during transportation. Of the 106 patients whose spontaneous circulation returned at the hospital, only 6 (5.7%) received mild therapeutic hypothermia. During the study period, 31 patients (4%) survived to discharge from hospitals, and 6 of these discharged patients (19.4%) showed favorable neurologic outcomes. CONCLUSION: While the survival rate from OHCA in Ansan is very low, this study provides basic information needed to create improvements. Our analysis suggests that multiple variables contribute to the low OHCA survival rate. Several of these variables are modifiable; addressing them is a clear first step toward strengthening the chain of survival from OCHA in Ansan.

Dry-spray deposition of TiO2 for a flexible dye-sensitized solar cell (DSSC) using a nanoparticle deposition system (NPDS).

TiO2 powders were deposited on indium tin oxide (ITO) coated polyethylene terephthalate (PET) substrates for application to the photoelectrode of a dye-sensitized solar cell (DSSC). In the conventional DSSC manufacturing process, a semiconductor oxide such as TiO2 powder requires a sintering process at higher temperature than the glass transition temperature (T(g)) of polymers, and thus utilization of flexible polymer substrates in DSSC research has been constrained. To overcome this restriction related to sintering, we used a nanoparticle deposition system (NPDS) that could produce a thin coating layer through a dry-spray method under atmospheric pressure at room temperature. The powder was sprayed through a slit-type nozzle having a 0.4 x 10 mm2 rectangular outlet. In order to determine the deposited TiO2 thickness, five kinds of TiO2 layered specimens were prepared, where the specimens have single and double layer structures. Deposited powders on the ITO coated PET substrates were observed using FE-SEM and a scan profiler The thicker TiO2 photoelectrode with a DSSC having a double layer structure showed higher energy efficiency than the single layer case. The highest fabricated flexible DSSC displayed a short circuit current density J(sc) = 1.99 mA cm(-2), open circuit voltage V(oc) = 0.71 V, and energy efficiency eta = 0.94%. These results demonstrate the possibility of utilizing the dry-spray method to fabricate a TiO2 layer on flexible polymer substrates at room temperature under atmospheric pressure.

Fabrication of dye-sensitized solar cell (DSSC) using different particle sizes of TiO2 deposited via nano-particle deposition system (NPDS).

TiO2 layers were fabricated using a nano-particle deposition system (NPDS) on transparent conductive oxide (TCO) glass for dye sensitized solar cells (DSSCs). Conventionally, TiO2 paste for working electrodes has been fabricated using paste type methods. The fabricated paste composed of a mixture of nano-sized TiO2 powders, binders and solutions is then painted on TCO glass. After drying, the TiO2 layer on TCO glass is sintered to make a path for electron transfer. TiO2 layers formed by this paste type method require numerous steps, which can be time consuming. In this study, TiO2 powders were sprayed directly on TCO glass using NPDS in order to simplify the fabrication steps. To improve porosity and produce scattering layers, commercial nanocrystalline TiO, powders with different sizes were alternately deposited. Moreover, powders with different sizes were mixed and deposited on the TCO glass. The results indicate that the DSSCs with a TiO2 layer composed of different particle sizes had better cell performance than the cells assembled with single-sized TiO2 particles. Therefore, this study shows that a dry TiO2 coating process is possible for DSSC fabrication to improve its cell efficiencies, and this method can easily be applied on flexible substrates since NPDS is a room-temperature deposition process.