Delayed appendectomy versus early appendectomy in the treatment of acute appendicitis: a retrospective study

BACKGROUND: The controversy still exists about the timing of operation for appendicitis. The aim of this study was to compare the outcomes between early appendectomy and delayed appendectomy and assess the feasibility of delayed operation. METHODS: The medical records of patients with acute appendicitis who received operation between January 1, 2011 and December 31, 2011, were retrospectively reviewed. Outcome measures were white blood cell (WBC) count at postoperative first day, time to soft diet, complication rate, surgical site infection (SSI) rate, length of hospital stay, and readmission within 30 days. RESULTS: During the study period, a total of 478 patients underwent appendectomies, and 145 patients were excluded, leaving 333 who met inclusion criteria. Based on the time from arrival at hospital to incision, they were divided into two groups: 177 (53.2%) in group A and 156 (46.8%) in group B. There were no significant differences in preoperative demographics and clinical data between two groups. The mean WBC count at postoperative first day of group B were lower than that of group A (p = 0.0039). There were no significant differences in time to soft diet, length of postoperative hospital stay, complication rate, and readmission rate between two groups. SSI including intra-abdominal abscess was also shown no significant difference (Group A, 1.7% and Group B, 3.9%; p = 0.3143). CONCLUSIONS: This study revealed that delayed appendectomy was safe and feasible for adult patient although the clinical outcomes of delayed appendectomy were not superior to those of early appendectomy. We suggest that surgeons would decide the appropriate timing of appendectomy with consideration other situations such as available hospital resources

Fabrication and Characterization of Metal-Loaded Mixed Metal Oxides Gas Sensors for the Detection of Hazardous Gases

This study concerns gas sensors that may protect individuals by detecting hazardous gases that may be generated in hot spaces (≥50°C) with residues of organic waste. We investigated the responses and selectivities of the sensors to different kinds of hazardous gases such as acetaldehyde, toluene and hydrogen sulfide. We also investigated operating temperatures and catalysts for the sensors. The thick film semiconductor sensors that detected some hazardous gases were prepared using nano-sized sensing material powders (SnO2, WO3, ZnO) that were prepared through sol-gel and precipitation methods. The nano-sized sensing materials were blended with various amounts of metal oxides (SnO2, ZnO, WO3) and coated with transition metals (Pt, Pd, Ru, Au, Ag, Cu and In). The metal oxide thick films were fabricated on an Al2O3 plate with a Ni-Cr heater and a Pt electrode through a screen-printing method. Morphologies, compositions, phases, surface areas and particle sizes of sensor compounds were examined by SEM, EDS, XRD and BET analysis. The investigated response to the various hazardous vapors was expressed as the value of Ra/Rg, where Ra and Rg are the resistance of the sensor material in the air and in hazardous gas, respectively