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Background: Although small- and medium-sized hospitals comprise most healthcare providers in South Korea, data on antibiotic usage is limited in these facilities. We evaluated the pattern of antibiotic usage and its appropriateness in hospitals with <400 beds in South Korea. Methods: A multicenter retrospective study was conducted in 10 hospitals (6 long-term care hospitals, 3 acute-care hospitals, and 1 orthopedic hospital), with <400 beds in South Korea. We analyzed patterns of antibiotic prescription and their appropriateness in the participating hospitals. Data on the monthly antibiotic prescriptions and patient days for hospitalized patients were collected using electronic databases from each hospital. To avoid the effect of the COVID-19 pandemic, data were collected from January to December 2019. For the evaluation of the appropriateness of the prescription, 25 patients under antibiotic therapy were randomly selected at each hospital over 2 separate periods. Due to the heterogeneity of their characteristics, the orthopedics hospital was excluded from the analysis. The collected data were reviewed, and the appropriateness of antibiotic prescriptions was evaluated by 5 specialists in infectious diseases (adult and pediatric). Data from 2 hospitals were assigned to each specialist. The appropriateness of antibiotic prescriptions was evaluated from 3 aspects: route of administration, dose, and class. If the 3 aspects were ‘optimal,’ the prescription was considered ‘optimal.’ If only the route was ‘optimal,’ and the dose and/or class was ‘suboptimal,’ but not ‘inappropriate,’ it was considered ‘suboptimal.’ If even 1 aspect was ‘inappropriate,’ it was classified as ‘inappropriate.’ Results: The most commonly prescribed antibiotics in long-term care hospitals was fluoroquinolone, followed by β-lactam/β-lactamase inhibitor (antipseudomonal). In acute-care hospitals, these were third-generation cephalosporin, followed by first-generation cephalosporin and second-generation cephalosporin. The major antibiotics that were prescribed in the orthopedics hospital was first-generation cephalosporin. Only 2.3% of the antibiotics were administered inappropriately. In comparison, 15.3% of patients were prescribed an inappropriate dose. The proportion of inappropriate antibiotic prescriptions was 30.6% of the total antibiotic prescriptions. Conclusions: The antibiotic usage patterns vary between small- and medium-sized hospitals in South Korea. The proportion of inappropriate prescriptions exceeded 30% of the total antibiotic prescriptions.
A certain degree of pulmonary stenosis after total correction of tetralogy of Fallot has been considered acceptable. But the long-term outcomes are not well understood. We observed the natural course of immediate pulmonary stenosis and investigated related factors for progression.
Fifty-two patients with acceptable pulmonary stenosis immediately after operation were enrolled. Acceptable pulmonary stenosis was defined as peak pressure gradient between 15 and 45 mmHg by Doppler echocardiography. Latent class linear mixed model was used to differentiate patients with progressed pulmonary stenosis, and the factors related to progression were analysed.
Pulmonary stenosis progressed in 14 patients (27%). Between the progression group and no progression group, there were no significant differences in operative age, sex, and the use of the transannular patch technique. However, immediate gradient was higher in the progression group (32.1 mmHg versus 25.7 mmHg, p = 0.009), and the cut-off value was 26.8 mmHg (sensitivity = 65.3%, specificity = 65.8%). Main stenosis at the sub-valve was observed more frequently in the progression group (85.7% versus 52.6%, p = 0.027). Despite no difference in the preoperative pulmonary valve z value, the last follow-up pulmonary valve z value was significantly lower in the progression group (−1.15 versus 0.35, p = 0.002).
Pulmonary stenosis immediately after tetralogy of Fallot total correction might progress in patients with immediate pulmonary stenosis higher than ≥26.8 mmHg and the main site was sub-valve area.
We present a young soldier presenting with aborted sudden cardiac death, who was found to have concomitant hypertrophic cardiomyopathy and Wolff–Parkinson–White syndrome. Along with pathological haemodynamic features of hypertrophic cardiomyopathy, an easily-inducible re-entrant tachycardia was clearly documented in our patient. Given the fatal potential of supraventricular tachycardia in hypertrophic cardiomyopathy, we postulated that his tachyarrhythmia could potentially trigger the event. Upon his refusal to receive implantable cardioverter/defibrillator therapy, we ablated anatomical arrhythmogenic substrate instead, and he remained uneventfully over 3 years on β-blocker.
Both luminous efficiency and lifetime in blue fluorescence organic light
emitting devices (OLEDs) have been improved by modified HTMs with higher
LUMO energy levels. The LUMO energy levels of HTM were increased by
modifying substituent in HTM molecules. Two HTMs containing ortho and meta
biphenyl substituent and one HTM containing thiophene substituent were
synthesized via palladium catalyzed amine coupling reactions to compare with
a para biphenyl substituent HTM-1 as a standard molecule. According to TDDFT
calculations, these three modified HTMs showed 0.05-0.15 eV higher LUMO
energy levels compared to the para biphenyl substituent HTM-1. The luminous
efficiency and the lifetime (LT90) of OLEDs using HTM-2 at 500
cd/m2 have been enhanced up to 20 % and 52 %, respectively,
compared to the standard device using HTM-1.
To enhance the lifetime of large-sized active matrix organic light emitting
diodes (AMOLEDs), we developed a liquid desiccant for encapsulation. The
liquid desiccant was prepared by mixing nano-sized calcium oxide (CaO)
powders and silicone binder including polyalkylalkenylsiloxane,
polyalkylhydrogensiloxane and platinum compound. It was confirmed that
liquid desiccant had an effect on absorption of penetrated moisture and
oxygen through calcium tests. Also, the test cells encapsulated with only
epoxy sealant dispensed at the edge of the cell developed dark spots within
100 hrs, which grew larger with time at 85 oC and 85 % R.H. On the other hand, the test cell sealed with epoxy
sealant and liquid desiccant showed no dark spots and retained 97% of its
initial luminance even after being stored for 800 hrs at 85 oC and 85 % R.H. Furthermore, the accelerating storage lifetimes of
31-inch bottom-emitting AMOLEDs with epoxy sealant and liquid desiccant
showed about 1000 hrs. These results suggest that the liquid desiccant can
be applied to encapsulation of large-sized AMOLEDs.
We investigated effects of thermal annealing on Ru films deposited on the 8 inch Si substrates using a volatile liquid-phase Ru precursor, tricarbonyl-1,3-cyclohexadienyl ruthenium (Ru(CO)3(C6H8)) by an atomic layer deposition (ALD) technique. Structural and electrical properties of the films were characterized by scanning probe microscopy, X-ray diffractometry, sheet resistance. Grazing incidence X-ray diffraction (GIXRD) patterns show typical Ru hexagonal polycrystalline peaks as annealing temperature was increased. At the highest annealing temperature condition, Ta = 700 °C electrical resistivity become 6 times less than in as-deposited films.
The structure and crystal growth of the silicon thin film deposited by e-beam evaporator have been studied with use of scanning electron microscopy (SEM), x-ray diffraction and transmission electron microscopy (TEM). The silicon thin film is deposited at room temperature for flexible display. It is found that the silicon film deposited by e-beam evaporator has polysilicon structure by scanning electron microscopy (SEM). SEM image also shows that grain size of the silicon film is about 50nm. X-ray diffraction of the silicon thin film represents that the orientation of the silicon film is (201). We have also investigated the structure and the crystal growth of the silicon film after the silicon film is irradiated by XeCl excimer laser with various energy densities. Transmission electron microscopy shows that the irradiated silicon thin film has low intra-grain defects and sharp grain boundary.
In the scribe lane, which is located at the frame neighboring two chips, most of the test patterns for monitoring electrical characteristics of memory device as well as various key patterns for photo process are formed. The pattern density of these regions is lower than that of the main chip area, and cause nitride erosion by dishing phenomena during HSS STI CMP process. Nitride erosion occurred in the scribe lane region, could the affect erosion properties of cell region in main chip area, results in within die remain nitride variation and marginal fail in device operation. In this work, in order to prevent these problems, pattern design in the scribe lane was modified so as not to occurs within die remain nitride variation. The effects of improvement in within die remain nitride variation were investigated by FIB-TEM analysis and its correlation with electrical properties were explained.
We have successfully obtained large lateral grains with well-controlled grain boundary. The proposed excimer laser annealing (ELA) method produces 2-dimensionally controlled grain growth because the temperature gradient is induced in two directions. Along the channel direction, the floating active structure produces large thermal gradient due to very low thermal conductivity of the air-gap. Along the perpendicular direction to the channel, the surface tension effect also produces thermal gradient. The proposed ELA method can control the grain boundary perpendicular and parallel to current path with only one laser irradiation.
We have fabricated high-mobility TFTs with large lateral grains and investigated the variation of drain current with increasing temperature. The activation energy of drain current in large grain TFTs is found to be higher under the off-state and lower under the on-state than that in small grain TFTs. The field-effect mobility during the on-state is reduced with increasing temperature due to a lattice scattering inside grain. Because the proposed device has large lateral grain in the channel region, the lattice scattering inside the grain would be dominant, which is similar to single crystal Si MOSFETs.
XeCl excimer laser was irradiated on metal induced laterally crystallized (MILC) polycrystalline silicon (poly-Si) film in order to eliminate the intra-grain defects of MILC poly-Si film which incorporated 2 μm wide metal induced crystallized (MIC) poly-Si line pattern. On the irradiation of the laser beams, different melt and recrystallization phenomena were observed in the MILC and the MIC poly-Si region due to the Ni content difference in each film. The transmission electron microscopy (TEM) and secondary ion mass spectrometry (SIMS) measurements indicated that the melting temperature of the poly-Si film decreased as the Ni content increased. With the laser irradiation energy density of 370 mJ/cm2, 2 μm long defect-free poly-Si grain was successfully grown in the MILC poly-Si due to the melting temperature variation at the MILC-MIC poly-Si boundary.
We have proposed and fabricated a novel poly-Si TFT that is integrated into the gate-data line-crossover in order to increase aperture ratio and to decrease signal delay of AMLCD panel and electrical characteristics of TFT integrated into gate-data line-crossover almost are identical to conventional TFT. The aperture ratio of AMLCD panel was increased considerably because the TFT was located under the opaque metal line. We employed a low dielectric air-gap between the gate-data line crossover, which reduced a capacitance between the gate and data lines so that the RC signal delay of the data line is decreased significantly. Our experimental result shows that the fabricated TFT was successfully operated and the proposed structure found to reduce the RC signal delay has been reduced by factor of 9 compared with conventional AMLCD panel that employs SiO2 for insulator between gate and data lines.
We report a new excimer laser annealing method by employing selectively floating a-Si active layer structure in order to increase the grain size of poly-Si film. The floating a-Si region blocks the heat conduction into the underlying substrate due to high thermal-insulating property of an air so that the lateral temperature gradient is successfully induced by the proposed simple air-gap structure. Our experimental results show that large grains were grown in the lateral direction from the edge to the center of the floating active region. The large grains exceeding 4 m were successfully obtained with only one laser irradiation.
SrTiO3 thin films were prepared on Si(p-type 100) and Pt/SiO2/Si substrates using ECR plasma (or without ECR plasma) assisted MOCVD. Sr(TMI-D)2 and Ti-isopropoxide were used as Sr and Ti metal organic sources, respectively. Perovskite SrTiO3 films were obtained at relatively low temperature of 500°C (using ECR oxygen plasma. Experimental results indicated that higher deposition temperature and ECR oxygen plasma increase the crystallinity, the dielectric constant and the leakage current density. The dielectric constant and the dielectric loss were 222 and 0.04, respectively, for 1234 Å thin SrTiO3 film (Sr/(Sr+Ti)=0.5). The leakage current density was 3.78 × 10−7 A/cm2 at 1.0V, and the dielectric breakdown field was 0.57MV/cm. SEM analyses showed that SrTiO3 films have a uniform and fine grain structure. In terms of step coverage, a lateral step coverage of 50% at 0.8 μm step (the aspect ratio was 1) was obtained with the thickness uniformity of ± 0.5% and the composition uniformity of ±1.2% at 4′′ wafer.
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