Background: Data on antimicrobial use at the national level is crucial to establish domestic antimicrobial stewardship policies and enable medical institutions to benchmark against each other. This study aimed to analyze antimicrobial use in Korean hospitals. Methods: We investigated the antimicrobials prescribed in Korean hospitals between 2018 and 2021, using data from the Health Insurance Review and Assessment. Primary care hospitals (PCHs), secondary care hospitals (SCHs), and tertiary care hospitals (TCHs) were included in this analysis. Antimicrobials were categorized according to the Korea National Antimicrobial Use Analysis System (KONAS) classification, which is suitable for measuring antimicrobial use in Korean hospitals. Results: Out of more than 1,900 hospitals, PCHs and TCHs represented the largest and lowest percentage of hospitals, respectively. The most frequently prescribed antimicrobial in 2021 was piperacillin/β-lactamase inhibitor (9.3%) in TCHs, ceftriaxone (11.0%) in SCHs, and cefazedone (18.9%) in PCHs. Between 2018 and 2021, the most used antimicrobial class according to the KONAS classification was ‘broad-spectrum antibacterial agents predominantly used for community-acquired infections’ in TCHs and SCHs, and 'narrow spectrum beta-lactam agents' in PCH. Total consumption of antimicrobials has decreased from 951.7 to 929.9 days of therapy (DOT)/1,000 patient-days in TCHs and from 817.8 to 752.2 DOT/1,000 patient-days in SCHs during study period, but not in PCHs (from 504.3 to 527.2 DOT/1,000 patient-days). Moreover, in 2021, while use of reserve antimicrobials has decreased from 13.6 to 10.7 DOT/1,000 patient-days in TCHs and from 4.6 to 3.3 DOT/1,000 patient-days in SCHs, it has increased from 0.7 to 0.8 DOT/1,000 patient-days in PCHs. Conclusion: This study confirms that antimicrobial use differs by hospital type in Korea. Recent increases of use of antimicrobials, including reserve antimicrobials, in PCHs reflect the challenges that must be addressed.

Market demand for touch panel/lens has been exceptionally high for the recent years due to smartphones, tablet PCs, etc. Among the available technologies to envision touch functionality, capacitive touch screen has received the great attention due to the various superiorities over the competing ones. Capacitive touch screen features two transparent conductive electrodes, such as ITO (indium tin oxide). However, the difference in refractive indices of ITO, substrate, and air, ITO pattern is clearly visible if there is no proper countermeasure. Most of touch screen makers and ITO substrate supplier utilize “index-matching technology” to prevent this phenomenon.

Even though of the attempts to minimize visible ITO pattern in final product, there are many technical and process challenges. In this study, the causes around visible ITO pattern were investigated to understand and provide the proper countermeasures.

One of the possible causes for visible ITO pattern was improper annealing process in ITO especially for film substrate. According to XPS (X-ray photoelectron spectroscopy)/ESCA (electron spectroscopy for chemical analysis) and other analysis results, ITO, which is normally deposited through sputtering, is not fully transformed to oxidized state. After aligning and adjusting annealing condition, acknowledged visible ITO pattern was disappeared.

Other causes for visible patterns were also discussed in detail, and the relevant countermeasures were provided.

A gold and aluminum layer was investigated as an anode for organic light-emitting devices (OLEDs). By pretreating the ultrathin aluminum layer in an oxygen (O2) plasma, the hole injection from the metal anode to the organic layer was greatly enhanced. The fabricated OLEDs demonstrated improved current density and luminance characteristics as compared with other devices using a gold anode and an aluminum layer not treated with an oxygen plasma.

Pt thin films of various thicknesses (30 nm ∼ 200 nm) were deposited on Si wafers with SiO2, Ti, TiO2, or IrO2 buffer layers at various temperatures (room temperature ∼200 °C) by a direct current magnetron sputtering process. The Pt films showed a strong (111)-preferred texture irrespective of the thickness, under-layer, and growth temperature. The authors previously reported [J-E. Lim, D-Y. Park, J.K. Jeong, G. Darlinski, H.J. Kim, and C.S. Hwang, Appl. Phys. Lett. 81, 3224 (2002)] that the films were composed of three kinds of grains with slightly different (111) lattice parameters (bulklike, 1.0% and 2.1% larger). This study details the microstructural variations of the Pt films according to the variations of experimental parameters. The different deposition conditions produced slightly different crystalline structures, but the three different (111) lattice parameters were always found. Epitaxial (200) Pt films on a (200) MgO substrate and a highly (111) textured Au thin film on a SiO2/Si did not show the same splitting in the lattice parameter. The grains with 1.0% and 2.1% larger (111) lattice parameter almost disappeared after postannealing at 1000 °C. However, surface chemical binding of the Pt film before and after annealing was unchanged. Therefore, it is believed that the lattice parameter splitting in the (111) textured Pt film originated from the interfacial grains with the distorted crystal structure due probably to growth stress.

(200)-oriented Pt thin films were deposited on SiO2/Si substrates by dc magnetron sputtering using Ar/O2 gas mixtures. Oxygen incorporation into Pt films changed deposition rate, resistivity, stress, and preferred orientation of the films. Increase in film resistivity and decrease in tensile stress were presumed to be the results of the incorporated oxygen into grain boundaries, while the change of preferred orientation resulted from the oxygen incorporation into the Pt lattice. The preferential growth of (200) planes with less total strain energy from the incorporated oxygen resulted in strong (200) preferred orientation in Pt films.

Highly (200)-oriented Pt films on SiO2/Si substrates were successfully prepared by a combination of a dc magnetron sputtering using Ar/O2 gas mixtures and subsequent controlled annealing. The intensity ratio of (200) to (111) planes (I200/I111) was over 200. The (200)-oriented Pt microcrystallites were less susceptible to amorphization due to their lower strain energy with oxygen incorporation than (111)-oriented ones. The controlled grain growth from the selected (200)-oriented seed microcrystallites during subsequent annealing provided a kinetic pathway where grain growth of the seed microcrystallites was predominant, while suppressing the nucleation of surface energy-driven, (111)-oriented seed microcrystallites and subsequent (111) preferred orientation.

Monoclinic gallium oxide (β-Ga2O3) nanowires were catalytically synthesized by electric arc discharge of GaN powders mixed with a small amount (less than 5 %) of transition metals under a pressure of 500 Torr (80 %-Ar + 20 %-O2). Scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM) images showed that the average diameter of the wires were about 30 nm and their lengths were as long as up to one hundred micrometer, resulting in extremely large aspect ratio. Fourier diffractogram was indicative of single crystalline nature of the β-Ga2O3 wire. HRTEM image also showed β-Ga2O3 with twin defects at the center of the wire which might play as nucleation seeds. Both X-ray diffraction (XRD) patterns and FT-Raman spectra of the wires identified the observed nanowires as monoclinic crystalline gallium oxides.

In this study, defect-free Pt films with good adhesion were deposited on SiO2/Si substrates by a two-step magnetron sputtering. This method consists of the first sputtering step using Ar/O2 gas mixture and the second step using Ar. After two-step deposition, an annealing process was followed at 600-1,000 °C in ambient atmosphere. In the first step, oxygen containing Pt films were deposited. Oxygen incorporated in the Pt films completely diffused out during the high temperature annealing. After the annealing process, the film became dense without catastrophic failures such as hillock, pinhole or buckling. Adhesion strength of films produced by this process was good enough to pass a tape test. It is believed that the good adhesion and the observed microstructural evolution are related to the oxygen in Pt films introduced during the first sputtering step. Adhesion, microstructural evolution and the role of oxygen in Pt films are briefly discussed.

Pt thin films were deposited by a DC magnetron sputtering with Ar/O2 gas mixtures. Due to the oxygen incorporation into the Pt films, deposition rate and resistivity of as-deposited Pt thin films increased with oxygen fraction in the sputtering gas. No peaks from crystalline Pt oxides were observed by x-ray diffraction (XRD) and excessive oxygen incorporation into Pt lead to an amorphous Pt oxide formation. More oxygen could be incorporated in the Pt thin films deposited at lower temperatures and at higher total pressures. Incorporated oxygen was completely removed after an annealing at 800 °C for an hour in air ambient, as the resistivity of the Pt thin films recovered their bulk resistivity values. Tensile stress of the Pt films decreased with oxygen incorporation, and approached a saturation level at high resistivity of the films, presumably due to the formation of amorphous Pt oxides.

Platinum(Pt) films were sputter-deposited on Si02/Si substrates under the mixed gas atmosphere of Ar and O2. Under certain deposition conditions, the films were oriented such that the (100) direction is normal to the substrate surface. The formation of the (100) texture was affected by the gas pressure and film thickness. After annealing at 650 °C for 1 hour, (100) oriented Pt films with the resistivity of pure Pt were obtained. The annealed Pt films all passed a tape adhesion test and had no defects such as hillocks or pinholes. The experimental results from this work are presented.