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Severe patients visited regional emergency centers more frequently during the COVID-19 period, and disposition status warranting admission to the intensive care unit or resulting in death was more common during the COVID-19 period. This study was conducted to compare the characteristics and severity of patients, and emergency department length of stay before and after the COVID-19 outbreak. Subjects were 75,409 patients who visited the regional emergency medical center from 1 February 2019 to 19 January 2020 and from 1 February 2020 to 19 January 2021. Data was analyzed using the SPSS/WIN 22.0 program. The significance level was p < 0.05. The chi-square test and t-test were used for variables, and Cramer V was used for correlation. We found that the total number of patients visiting the emergency room decreased by 37.6% after COVID-19, but emergency department length of stay among severely ill patients increased by 203.7%. Additionally, the utilization rate of 119 ambulances and relatively more severe patients increased by 9.0% and by 2.1%. More studies about emergency department designs and operational programs should be conducted for better action not only during regular periods but also during periods of pandemic.

The purpose of the study was to compare clinical characteristics and mortality among adults infected with human coronaviruses (HCoV) 229E and OC43. We conducted a retrospective cohort study of adults (≥ 18 years) admitted to the ward of a university teaching hospital for suspected viral infection from October 2012 to December 2017. Multiplex real-time polymerase chain reaction (PCR) was used to test for respiratory viruses. Multivariate logistic regression was used to compare mortality among patients with HCoV 229E and HCoV OC43 infections. The main outcome was 30-day all-cause mortality. Of 8071 patients tested, 1689 were found to have a respiratory virus infection. Of these patients, 133 had HCoV infection, including 12 mixed infections, 44 HCoV 229E infections, and 77 HCoV OC43 infections. HCoV 229E infections peaked in January and February, while HCoV OC43 infections occurred throughout the year. The 30-day all-cause mortality was 25.0% among patients with HCoV 229E infection, and 9.1% among patients with HCoV OC43 infection (adjusted odds ratio: 3.58, 95% confidence interval: 1.19–10.75). Infections with HCoVs 229E and OC43 appear to have different seasonal patterns, and HCoV 229E might be more virulent than HCoV OC43.

Transparent conductive films (TCFs) were fabricated through bar-coating with a water-in-toluene emulsion containing Ag nanoparticles (AgNPs). Morphological changes in the self-assembled TCF networks under different emulsion formulations and coating conditions and the corresponding optoelectrical properties were investigated. In preparing various emulsions, the concentration of AgNPs and the water weight fraction were important factors for determining the size of the water droplets, which plays a decisive role in controlling the optoelectrical properties of the TCFs affected by open cells and conductive lines. An increased concentration of AgNPs and decreased water weight fraction resulted in a decreased droplet size, thus altering the optoelectrical properties. The coating conditions, such as coating thickness and drying temperature, changed the degree of water droplet coalescence due to different emulsion drying rates, which also affected the final self-assembled network structure and optoelectrical properties of the TCFs. Systematically controlling various material and process conditions, we explored a coating strategy to enhance the optoelectrical properties of TCFs, resulting in an achieved transmittance of 86 ± 0.2%, a haze of 4 ± 0.2%, and a sheet resistance of 35 ± 2.8 Ω/□. TCFs with such optimal properties can be applied to touch screen fields.

We address the absence of reliable tests on contract analyzers of smart contracts and present a systematic method to diversify test cases by combining smart-contract-specific bugs and static analysis barriers in this paper. Using contract analyzers is the most practical solution for building a secure blockchain service, but they are relatively immature and lacking stable performance metrics. Traditionally, performance reports only compare static contract analyzers with pre-defined test cases, such as the Juliet test suite. However, building such test suites is burdensome for smart contracts, which are frequently change. In this paper, we propose an automated method to assess contract analyzers of smart contracts by diversifying test cases. In the experimental results, we identified nine erroneous alarms in the state-of-the-art contract analyzers with automatically generated test cases on five vulnerabilities.

The survey was conducted in five areas including Namsan district (21.00 ㎢), Tohamsan district (76.95 ㎢), Seoak district (4.30 ㎢), Hwarang district (3.90 ㎢), and Sogumgang district (6.8 ㎢) that are designated as Gyeongju National Park. The bird population in the forests and surrounding areas was examined through surveys performed three times in June, August, and January 2017. A total of 36 families, 88 species, and 7,724 individuals of birds were observed, and the dominant species were Passer montanus (19.43%), Corvus frugilegus (10.97%), Anas poecilorhyncha (8.08%), Streptopelia orientalis (7.65%), Paradoxornis webbianus (6.59%), and Microscelis amaurotis (5.80%). The number of bird species observed during the survey was the highest in the spring with 60 species, 50 species in summer, and the lowest in the winter with 45 species. The number of species, population, species diversity, and species richness of birds in Gyeongju National Park have been increasing compared with those observed 20 years ago. Keywords: Dominant species, Species diversity, Species richness

Sediment bioelectrochemical systems (SBESs) can be integrated into brackish aquaculture ponds for in-situ bioremediation of the pond water and sediment. Such an in-situ system offers advantages including reduced treatment cost, reusability and simple handling. In order to realize such an application potential of the SBES, in this laboratory-scale study we investigated the effect of several controllable and uncontrollable operational factors on the in-situ bioremediation performance of a tank model of a brackish aquaculture pond, into which a SBES was integrated, in comparison with a natural degradation control model. The performance was evaluated in terms of electricity generation by the SBES, Chemical oxygen demand (COD) removal and nitrogen removal of both the tank water and the tank sediment. Real-life conditions of the operational parameters were also experimented to understand the most close-to-practice responses of the system to their changes. Predictable effects of controllable parameters including external resistance and electrode spacing, similar to those reported previously for the BESs, were shown by the results but exceptions were observed. Accordingly, while increasing the electrode spacing reduced the current densities but generally improved COD and nitrogen removal, increasing the external resistance could result in decreased COD removal but also increased nitrogen removal and decreased current densities. However, maximum electricity generation and COD removal efficiency difference of the SBES (versus the control) could be reached with an external resistance of 100 Ω, not with the lowest one of 10 Ω. The effects of uncontrollable parameters such as ambient temperature, salinity and pH of the pond (tank) water were rather unpredictable. Temperatures higher than 35°C seemed to have more accelaration effect on natural degradation than on bioelectrochemical processes. Changing salinity seriously changed the electricity generation but did not clearly affect the bioremediation performance of the SBES, although at 2.5% salinity the SBES displayed a significantly more efficient removal of nitrogen in the water, compared to the control. Variation of pH to practically extreme levels (5.5 and 8.8) led to increased electricity generations but poorer performances of the SBES (vs. the control) in removing COD and nitrogen. Altogether, the results suggest some distinct responses of the SBES under brackish conditions and imply that COD removal and nitrogen removal in the system are not completely linked to bioelectrochemical processes but electrochemically enriched bacteria can still perform nonbioelectrochemical COD and nitrogen removals more efficiently than natural ones. The results confirm the application potential of the SBES in brackish aquaculture bioremediation and help propose efficient practices to warrant the success of such application in real-life scenarios.

In this study, we investigated the potential of using sediment bioelectrochemical systems (SBESs) for in situ treatment of the water and sediment in brackish aquaculture ponds polluted with uneaten feed. An SBES integrated into a laboratory-scale tank simulating a brackish aquaculture pond was established. This test tank and the control (not containing the SBES) were fed with shrimp feed in a scheme that mimics a situation where 50% of feed is uneaten. After the SBES was inoculated with microbial sources from actual shrimp pond sediments, electricity generation was well observed from the first experimental week, indicating successful enrichment of electrochemically active bacteria in the test tank sediment. The electricity generation became steady after 3 weeks of operation, with an average current density of 2.3 mA/m2 anode surface and an average power density of 0.05 mW/m2 anode surface. The SBES removed 20-30% more COD of the tank water, compared to the control. After 1 year, the SBES also reduced the amount of sediment in the tank by 40% and thus could remove approximately 40% more COD and approximately 52% more nitrogen from the sediment, compared to the control. Insignificant amounts of nitrite and nitrate were detected, suggesting complete removal of nitrogen by the system. PCR-DGGE-based analyses revealed the dominant presence of Methylophilus rhizosphaerae, Desulfatitalea tepidiphila and Thiothrix eikelboomii, which have not been found in bioelectrochemical systems before, in the bacterial community in the sediment of the SBES-containing tank. The results of this research demonstrate the potential application of SBESs in helping to reduce water pollution threats, fish and shrimp disease risks, and thus farmers' losses.

Recently, there has been a growing interest in magnetic levitation. In respect to these expectations, lots of applications using magnetic levitation are developed. In this paper, the reference model, which is consisted of four electromagnets and permanent magnets, is replaced with two type of magnetic levitation systems by using only permanent magnets: the attraction-based levitation and the repulsion-based levitation. Two types of magnetic levitation system are analyzed using finite-element method and the stability with respect to vertical and lateral direction are compared. The analyzed results suggest the guideline to choose proper types of magnetic levitation for the purpose of the application.

Predicting hospital readmissions among diabetic patients has been of substantial interest to many researchers and health decision makers to provide quality and cost effective health care. In this paper, we optimize an efficient classifier for hospital readmission prediction within 30 days of discharge, the hybrid fuzzy weighted k-nearest neighbor (HFWkNN) method. The optimization is performed through the hyperparameter γ, e and emin introduced in the membership function of HFWkNN. These hyperparameters are important since they directly control the behavior of the training phase and significantly affect the performance of the method. A relationship is established between the performance of the proposed HFWkNN and the hyperparameters using two powerful optimization algorithms; grid search and random search. Experimental results show improved performance using the optimized hyperparameters in the resulting hospital readmission prediction model. To show that HFWkNN model can be generalized, the results are compared with those of several kNN-based algorithms using two additional classification datasets in addition to the hospital readmission dataset. They are IRIS dataset and breast cancer dataset. These are common benchmark sets with real-world data. The model so far achieved higher classification accuracy than FkNN model. The best hyperparameter values for HFWkNN with grid search are γ=0.2249, e=1.112 and e min =0.01. Also, HFWkNN shows a performance of 80.00%, meaning that it has generalized well on the different data sets.

Objective. Excessive daytime sleepiness (EDS) in emergency medicine (EM) residents is associated with patient safety. However, studies regarding EDS in EM residents are limited. The objective of this study was to identify the prevalence of EDS and its associated factors among EM residents. Methods. Epworth sleepiness scale scores, working hours per week (WHW), night working days per month, working environment, and depression were analyzed using data from the 2019 Korean Emergency Medicine Resident Survey. Results. The survey response rate was 63.8% (384/601). Among 241 respondents, the prevalence rate of EDS was 32.4%. Multivariable logistic regression analysis demonstrated that WHW (odds ratio [OR] = 1.03, 95% confidence interval [CI] = 1.01–1.06) and depression (OR = 3.64, 95% CI = 1.91–6.96) had increased ORs for EDS. Conclusions. Approximately one-third of EM residents had EDS. Depression and WHW were the associated factors.

We assessed infection control efforts by comparing data collected over 20 weeks during a pandemic under a dual-track healthcare system. A decline in non-COVID-19 patients visiting the emergency department by 37.6% (P

Specificity is a challenge in liquid biopsy and early diagnosis of various diseases. There are only a few biomarkers that have been approved for use in cancer diagnostics; however, these biomarkers suffer from a lack of high specificity. Moreover, determining the exact type of disorder for patients with positive liquid biopsy tests is difficult, especially when the aberrant expression of one single biomarker can be found in various other disorders. In this study, a SERS-based protein biomarker detection platform in a microfluidic chip and two machine learning algorithms (K-nearest neighbor and classification tree) are used to improve the reproducibility and specificity of the SERS-based liquid biopsy assay. Applying machine learning algorithms to the analysis of the expression level data of 5 protein biomarkers (CA19-9, HE4, MUC4, MMP7, and mesothelin) in pancreatic cancer patients, ovarian cancer patients, pancreatitis patients, and healthy individuals improves the chance of recognition for one specific disorder among the aforementioned diseases with overlapping protein biomarker changes. Our results demonstrate a convenient but highly specific approach for cancer diagnostics using serum samples.

Tin oxide/carbon nanocomposite (TOCNC) was synthesized using a liquid phase plasma method, to be used as the electrode of supercapacitor. Spherical tin oxide amorphous nanoparticles with the size of 5 nm were dispersed uniformly on activated carbon powder (ACP) surface. The quantity of tin oxide nanoparticle precipitate increased with increasing LPP duration and the specific capacitance of TOCNC increased with increasing LPP duration. The TOCNC prepared through the LPP process showed smaller resistances and larger initial resistance slopes than bare ACP and this effect was intensified by increasing the LPP process duration.

LIL (laser interference lithography), which does not require a mask, is an effective way to create a wide variety of periodic patterns by exposing two laser beams on a specimen. The LIL method can be used for a wide range of nano-pattern spacing by adjusting the laser intensity, exposure time, and development time. In addition, it has been used in many studies due to its advantage with regard to the forming of nanostructures over a large area in a short period of time. However, the existing LIL technique requires demanding precision levels to align the laser beam. In this paper, we attempt to solve this problem by using a prism laser interferometer to complement the complicated beam alignment of LIL. In this study, ma-p1205 PR-coated silicon wafers were exposed to a CW laser with 360 nm wavelength using a contact-type and a non-contact prism interferometer. A rectangular triangular prism and an equilateral triangular prism of N-BK7 were used, and periods of 300 nm and 260 nm were fabricated, respectively. The MATLAB and COMSOL programs were used to compare the theoretical values and fabricated patterns.