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We report our experience with an emergency room (ER) shutdown related to an accidental exposure to a patient with coronavirus disease 2019 (COVID-19) who had not been isolated.
A 635-bed, tertiary-care hospital in Daegu, South Korea.
To prevent nosocomial transmission of the disease, we subsequently isolated patients with suspected symptoms, relevant radiographic findings, or epidemiology. Severe acute respiratory coronavirus 2 (SARS-CoV-2) reverse-transcriptase polymerase chain reaction assays (RT-PCR) were performed for most patients requiring hospitalization. A universal mask policy and comprehensive use of personal protective equipment (PPE) were implemented. We analyzed effects of these interventions.
From the pre-shutdown period (February 10–25, 2020) to the post-shutdown period (February 28 to March 16, 2020), the mean hourly turnaround time decreased from 23:31 ±6:43 hours to 9:27 ±3:41 hours (P < .001). As a result, the proportion of the patients tested increased from 5.8% (N=1,037) to 64.6% (N=690) (P < .001) and the average number of tests per day increased from 3.8±4.3 to 24.7±5.0 (P < .001). All 23 patients with COVID-19 in the post-shutdown period were isolated in the ER without any problematic accidental exposure or nosocomial transmission. After the shutdown, several metrics increased. The median duration of stay in the ER among hospitalized patients increased from 4:30 hours (interquartile range [IQR], 2:17–9:48) to 14:33 hours (IQR, 6:55–24:50) (P < .001). Rates of intensive care unit admissions increased from 1.4% to 2.9% (P = .023), and mortality increased from 0.9% to 3.0% (P = .001).
Problematic accidental exposure and nosocomial transmission of COVID-19 can be successfully prevented through active isolation and surveillance policies and comprehensive PPE use despite longer ER stays and the presence of more severely ill patients during a severe COVID-19 outbreak.
The characteristics of dopant activation by sequential lateral solidification in poly-Si films is investigated using sheet resistance measurement and Raman measurement. Sheet resistance of n+ and p+ doped poly-Si films decreases exponentially as the laser energy increases. The minimum sheet resistance of n+ doped poly-Si films is 150 Ω/□ which is near to that of rapid thermal annealing (RTA) while the minimum sheet resistance of p+ doped poly-Si films is 180 Ω/□ which is less than a half to that of RTA. The sheet resistance of n+ and p+ doped poly-Si increases as the laser energy increases when the laser energy is above 573 mJ/cm2 at which the nucleation occurs. Raman signal of n+ doped poly-Si films shows single peak at 515 cm-1 with all laser energy and has maximum intensity at 566 mJ/cm2 laser energy. Raman signal of p+ doped poly-Si films shows single peak below 413 mJ/cm2 laser energy and double peak above 444 mJ/cm2 laser energy where the fully melting of p+ doped poly-Si film occurs.
The good field-emission properties of carbon nanotubes coupled with their high mechanical strength, chemical stability, and high aspect ratio, make them ideal candidates for the construction of efficient and inexpensive field-emission electronic devices. The fabrication process reported here has considerable potential for use in the development of integrated radio frequency amplifiers or field emission-controllable cold electron guns for field emission displays. This fabrication process is compatible with currently used semiconductor processing technologies. Micropatterned vertically aligned carbon nanotubes were grown on planar Si surface or inside the trenches, using chemical vapor deposition, photolithography, pulsed-laser deposition, reactive ion etching, and the lift-off method. To control the field-emission current by a 3rd electrode, the gate electrode, we grew carbon nanotubes inside the trenches. This triode-type structure is the best to realize the gray-scale carbon nanotube field emission. This carbon nanotube fabrication process can be widely applied for the development of electronic devices using carbon nanotube field emitters as cold cathodes and could revolutionize the area of field-emitting electronic devices such as RF amplifiers and field emission displays.
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