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        검색결과 2,191

        201.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        ASL estimation of public building is based on how appropriate the maximum age of the asset is derived based on the age record of the asset in the statistical data owned by public institutions. This is because we get a 'constrained' ASL by that number. And it is especially true because other studies have assumed that the building is an Iowa curve R3. Also, in this study, the survival rate is 1% as the threshold value at which the survival curve and the predictable life curve almost coincide. Rather than a theoretical basis, in the national statistical survey, the value of residual assets was recognized from the net value of 10% of the acquisition value when the average service life has elapsed, and 1% when doubling the average service life has elapsed. It is based on the setting mentioned above. The biggest constraint in fitting statistical data to the Iowa curve is that the maximum ASL is selected at R3 150%, and the 'constrained' ASL is calculated by the proportional expression on the assumption that the Iowa curve is followed. In like manner constraints were considered. First, the R3 disposal curve for the RCC(reinforced cement concrete) building was prepared according to the discarding method in the 2000 work, and it was jointly worked on with the National Statistical Office to secure the maximum amount of vintage data, but the lacking of sample size must be acknowledged. Even after that, the National Statistical Office and the Bank of Korea have been working on estimating the Iowa curve for each asset class in the I-O table. Another limitation is that the asset classification uses the broad classification of buildings as a subcategory. Second, if there were such assets with a lifespan of 115 years that were acquired in 1905 and disposed of in 2020, these discarded data would be omitted from this ASL calculation. Third, it is difficult to estimate the correct Iowa curve based on the stub-curve even if there is disposal data because Korea has a relatively shorter construction history, accumulated economic wealth since the 1980’s. In other words, “constrained” ASL is an under-estimation of its ASL. Considering the fact that Korea was an economically developing country in the past and during rapid economic development, environmental factors such as asset accumulation and economic ability should be considered. Korea has a short period of accumulation of economic wealth, and the history of 'proper' architectures faithful to building regulations and principles is short and as a result, buildings 'not built properly' and 'proper' architectures are mixed. In this study, ASL of RCC public building was estimated at 70 years.
        4,000원
        202.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Fermentation by Rhizopus spp. has been used as a traditional medicine for treating various inflammatory diseases. Allergic asthma is a chronic respiratory disease that is caused by an exaggerated immune response. This study was conducted to ascertain the anti-inflammatory effects of Rhizopus spp. fermentation extract (RU) on a mouse model of ovalbumin (OVA)-induced asthma. The animals were intraperitoneally injected OVA on day 1 and 7, followed by OVA intranasal inhalation on days 14 to 18. The animals were treated daily with RU (100 and 200 mg/kg) by oral gavage from day 18 to day 23. RU significantly decreased eosinophilia and the production of inflammatory cytokines and OVA specific immunoglobulin E in animals with asthma, along with reducing airway inflammation and mucus secretion in lung tissue. Histological changes in the lungs and levels of inflammatory mediators of allergic airway inflammation were evaluated. The regulatory effects of RU on type 2 helper T (Th2) cell activation were investigated. RU administration attenuated asthmatic changes such as inflammatory cell infiltration and mucus production, decreased the levels of Th2-related cytokines, and reduced Th2 cell activation. Administration of RU effectively reduced allergic responses in asthmatic mice, which is associated with regulating Th2 cell activation and differentiation. These results indicate that RU can attenuate the respiratory symptoms of asthma.
        4,000원
        203.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In additive manufacturing, the flowability of feedstock particles determines the quality of the parts that are affected by different parameters, including the chemistry and morphology of the powders and particle size distribution. In this study, the microstructures and flowabilities of gas-atomized heat-resistant alloys for additive manufacturing applications are investigated. A KHR45A alloy powder with a composition of Fe-30Cr-40Mn-1.8Nb (wt.%) is fabricated using gas atomization process. The microstructure and effect of powder chemistry and morphology on the flow behavior are investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and revolution powder analysis. The results reveal the formation of spherical particles composed of single-phase FCC dendritic structures after gas atomization. SEM observations show variations in the microstructures of the powder particles with different size distributions. Elemental distribution maps, line scans, and high-resolution XPS results indicate the presence of a Si-rich oxide accompanied by Fe, Cr, and Nb metal oxides in the outer layer of the powders. The flowability behavior is found to be induced by the particle size distribution, which can be attributed to the interparticle interactions and friction of particles with different sizes.
        4,000원
        204.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Bacterial phytopathogen Pectobacterium causes soft rot disease in several vegetable crops globally, resulting in heavy agricultural losses at both the pre and postharvest stages. The present work was carried out to screen Kimchi cabbage genetic resources conserved at the National Agrobiodiversity Center, Rural Development Administration, Korea, for resistance against the soft rot pathogen Pectobacterium carotovorum subsp. carotovorum KACC 21701 over a period of three years (from 2020 to 2022). Infection of the phytopathogen was carried out at four-leaf stage and for each accession, twenty-five plants per germplasm were infected with KACC 21701. Kimchi cabbage cultivars Wangmatbaechu, Seoulbaechu, and CR Kiyoshi were used as control. Seven-days post-infection, the Disease Index (DI) values were manually recorded from zero to four, zero matched perfectly heathy plants and four completely dead plants. The 682 accessions of Kimchi cabbage exhibited varying degrees of disease resistance to KACC 21701 and thirty accessions, exhibiting a DI≤2, were considered for replication studies. During the replication studies, four landrace germplasms (IT102883, IT120036, IT120044, and IT120048) and one cultivar (IT187919) were confirmed to be moderately susceptible to KACC 21701. Results of the preliminary screening as well as replication studies were documented for the all the 682 germplasms. Addition of such information to the passport data of stored germplasms might serve as potential bio-resource for future breeders and researchers to develop resistant varieties or study the mechanisms involved in resistance of plants to such phytopathogen.
        4,000원
        205.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Protein and peptide candidates are screened to apply therapeutic application as a drug. Ensuring that these candidates are delivered and maximized effectiveness is still challenging and a variety of studies are ongoing. As drug delivery system vehicles, cell-penetrating peptide (CPP) can deliver various kinds of cargo into the cell cytosol. In a previous study, we developed Ara27 CPP, which are a zinc knuckle family protein of Arabidopsis, and confirmed internalization in human dermal fibroblasts and human dental pulp stem cells at low concentration with short time treatment condition without any toxicity. Ara27, an amphipathic CPP, could be modified and utilized in the biomedical field excluding the risk of toxicity. Therefore, we would like to confirm the non-toxic induced penetrating ability of Ara27 in various cell lines. The purpose of this study was to screen the cell internalization ability of Ara27 in various cell lines and to confirm Ara27 as a promising core CPP structure. First, Ara27 was screened to confirm non-toxicity concentration. Then, fluorescence-labeled Ara27 was treated on human normal cell lines, cancer cell lines and animal cell lines to identify the cellular internalization of Ara27. Ara27 was well intracellular localized in all cell lines and the intensity of fluorescence was remarkably increased in time pass manner. These results indicate that Ara27 has the potential as a core structure for applications in various drug delivery systems.
        4,000원
        206.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Influenza A viruses (IAVs) are members of the family Orthomyxoviridae and genus Orthomyxovirus. Avian and mammalian species are the host of IAVs, which includes humans and dogs. Canine influenza virus (CIV) is an emerging pathogen that causes severe and acute respiratory diseases in dogs. This study monitored the antigen and antibody against CIV in dogs in the Republic of Korea (ROK) from 2016 to 2021. One thousand and seventy-two nasal swabs and 1,545 blood samples were collected from animal hospitals and animal shelters. Five nasal swabs in 2017 and seven in 2018 from stray dogs were positive for CIV according to RT-PCR. The prevalence of H3N2 CIV ranged from 9.5% to 24.8%, according to the hemagglutination inhibition (HI) assay. On the other hand, none of the serum samples from 2018 to 2021 showed seropositivity against the avian H5, H7, and H9 viruses. The HI titers for H3N2 ranged from 16 to 512. The distribution of HI titer 16–32 was 57.6% in seropositive samples. The pet dogs were vaccinated against CIV, but the stray and military dogs were unvaccinated. In 2017 and 2018, the seroprevalence of CIV in stray dogs was higher than in the other years, and viral RNA was detected in nasal swabs. It may mean previous exposure of stray dogs to CIV. With the increasing number of pet dogs and the close contact between humans and dogs, canines could serve as an intermediate host for transmitting IAVs to humans. Therefore, continuous surveillance of CIV is needed for public health and the potential emergence of novel zoonotic viruses.
        4,000원
        207.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Emotional labor, characterized by a dysfunctional type of emotional regulation called surface acting, has detrimental psychological consequences on employees, including depression and social anxiety. Because such disorders exhibit psychological characteristics manifested through brain activation, previous studies have succeeded in distinguishing individuals with depression and social anxiety from healthy controls using their functional connectivity characteristics. However, it has not been established whether the functional connectivity characteristics associated with emotional labor are distinguishable. Thus, we obtained resting-state fMRI data from participants in the emotion labor (EL) group and control (CTRL) group, and we subjected their whole-brain functional connectivity matrices to a linear support vector machine classifier. Our analysis revealed that the EL and CTRL groups could be successfully distinguished on the basis of individuals' connectivity patterns, and confidence in the classification was correlated with the scores on the depression and social anxiety scales. These results are expected to provide insight on the neurobiological characteristics of emotional labor and enable the sorting of employees undergoing adverse emotional labor utilizing neurobiological observations.
        4,600원
        208.
        2022.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The ambiguity of complex regional pain syndrome (CRPS) posed a challenge to many medical researchers in the early days after its discovery and continues to do so till date. The establishment of the Budapest Criteria of the International Association for the Study of Pain resolved certain queries on CRPS. Many aspects of CRPS, such as pathophysiology and etiology, remain unknown. Therefore, of these aspects, we focused on the genetic basis of CRPS. In this qualitative review, we summarized the recent findings on the genetic association of CRPS and analyzed the roles of genes identified in each study and limitations of the studies. In particular, we confirmed the reliability of each study by comparing the following research, which used the following control groups or the same candidate genes. Notably, specific phenotypes of CRPS with dystonia indicate a significant association with human leukocyte antigen (HLA)-DQ8. Further, HLA-DQ8, which is associated with aberrant CD4+ T-cell reaction, could be associated with CRPS etiology since an increased CD4+ T-cell population was reported in CRPS patients. In addition, matrix metalloproteinase (MMP)-9 found in genome-wide expression profiling is noteworthy since MMP-9 is associated with neuro-inflammatory reactions. Despite these suggestions on the genetic aspects of CRPS, the pathophysiology and etiology of CRPS may be polygenic and multifactorial, influenced by multiple genes and other factors. Further, some studies have suggested that CRPS phenotypes have different etiologies. Thus, further studies with the precise classification of CRPS on a unified basis and with a significant number of case groups are required
        4,000원
        213.
        2022.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nonalcoholic fatty liver disease (NAFLD) is recognized one of the leading metabolic diseases globally, and the younger age population with the disease is rapidly growing, especially in developed countries. Since there has been no approved medicine, losing weight is known to be the only best remedy to control or reverse the disease. Recently, the field of microbiome has attracted much attention to offer more practical choices for patients. Here, we provide experimental evidence that Streptococcus thermophilus LM1012 (LM1012), a safe probiotic strain, is effective for improving NAFLD indexes. In the methionine-choline deficient (MCD) diet induced C57BL/6 mouse model, administration of LM1012 promoted marked reductions of aspartate transaminase (23.8%), total bilirubin (27.8%), hydroxycholesterol (64.2%), triglyceride (29.7%) and IL-1β (68.3%) compared to the MCD diet alone group. Also, the histopathological data imply that LM1012 inhibited fat accumulation and inflammation in the liver, which are the key biomarkers for progression of the disease. Together, these findings suggest that human consumption of LM1012 as a healthy nutritional supplement, may be helpful in reducing the risk of liver damages in NAFLD patients.
        4,200원
        214.
        2022.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We complete the survey for finite-source/point-lens (FSPL) giant-source events in 2016–2019 KMTNet microlensing data. The 30 FSPL events show a clear gap in Einstein radius, 9 μas < θE < 26 μas, which is consistent with the gap in Einstein timescales near tE ∼ 0.5 days found by Mr´oz et al. (2017) in an independent sample of point-source/point-lens (PSPL) events. We demonstrate that the two surveys are consistent. We estimate that the 4 events below this gap are due to a power-law distribution of freefloating planet candidates (FFPs) dNFFP/d logM = (0.4 ± 0.2) (M/38 M⊕)−p/star, with 0.9 ≲ p ≲ 1.2. There are substantially more FFPs than known bound planets, implying that the bound planet power-law index γ = 0.6 is likely shaped by the ejection process at least as much as by formation. The mass density per decade of FFPs in the Solar neighborhood is of the same order as that of ‘Oumuamua-like objects. In particular, if we assume that ‘Oumuamua is part of the same process that ejected the FFPs to very wide or unbound orbits, the power-law index is p = 0.89 ± 0.06. If the Solar System’s endowment of Neptune-mass objects in Neptune-like orbits is typical, which is consistent with the results of Poleski et al. (2021), then these could account for a substantial fraction of the FFPs in the Neptune-mass range.
        5,800원
        215.
        2022.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We present a new method which constructs an Hi super-profile of a galaxy which is based on profile decomposition analysis. The decomposed velocity profiles of an Hi data cube with an optimal number of Gaussian components are co-added after being aligned in velocity with respect to their centroid velocities. This is compared to the previous approach where no prior profile decomposition is made for the velocity profiles being stacked. The S/N improved super-profile is useful for deriving the galaxy’s global Hi properties like velocity dispersion and mass from observations which do not provide sufficient surface brightness sensitivity for the galaxy. As a practical test, we apply our new method to 64 high-resolution Hi data cubes of nearby galaxies in the local Universe which are taken from THINGS and LITTLE THINGS. In addition, we also construct two additional Hi super-profiles of the sample galaxies using symmetric and all velocity profiles of the cubes whose centroid velocities are determined from Hermite h3 polynomial fitting, respectively. We find that the Hi super-profiles constructed using the new method have narrower cores and broader wings in shape than the other two super-profiles. This is mainly due to the effect of either asymmetric velocity profiles’ central velocity bias or the removal of asymmetric velocity profiles in the previous methods on the resulting Hi super-profiles. We discuss how the shapes (σn/σb, An/Ab, and An/Atot) of the new Hi super-profiles which are measured from a double Gaussian fit are correlated with star formation rates of the sample galaxies and are compared with those of the other two super-profiles.
        6,100원
        218.
        2022.10 구독 인증기관·개인회원 무료
        Radioactive waste generated in large quantities from NPP decommissioning has various physicochemical and radiological characteristics, and therefore treatment technologies suitable for those characteristics should be developed. Radioactively contaminated concrete waste is one of major decommissioning wastes. The disposal cost of radioactive concrete waste is considerable portion for the total budget of NPP decommissioning. In this study, we developed an integrated technology with thermomechanical and chemical methods for volume reduction of concrete waste and stabilization of secondary waste. The unit devices for the treatment process were also studied at bench-scale tests. The volume of radioactive concrete waste was effectively reduced by separating clean aggregate from the concrete. The separated aggregate satisfied the clearance criteria in the test using radionuclides. The treatment of secondary waste from the chemical separation step was optimally designed, and the stabilization method was found for the waste form to meet the final disposal criteria in the repository site. The final volume reduction rates of 56.4~75.4% were possible according to the application scenario of our processes under simulated conditions. The commercial-scale system designs for the thermomechanical and chemical processes were completed. Also, it was found that the disposal cost for the contaminated concrete waste at domestic NPP could be reduced by more than 20 billion won per each unit. Therefore, it is expected that the application of this technology will improve the utilization of the radioactive waste disposal space and significantly reduce the waste disposal cost.
        219.
        2022.10 구독 인증기관·개인회원 무료
        Recently, it is being carried out the project to evaluate the properties of materials harvested from nuclear reactor after the decommissioning of Kori Unit 1. However, it is not sufficient adequate machining equipment and remote machining technique to perform the projects for evaluation of materials harvested from nuclear reactor. Thus, it is required to develop the remote machining technique in hotcell to evaluate the mechanical properties of nuclear reactor materials. The machining technique should be performed inside a hotcell to evaluate mechanical properties of materials harvested from nuclear reactor and is essential to prevent radiation exposure of workers. Also, it is essential to design the apparatus and develop the machining process so that it can be operated with a manipulator and minimize contamination in hotcell. In this research, development of remote specimen machining technique in hotcell such as machining apparatus, technique and process for compact tension specimens of material harvested from nuclear reactor are described. Remote machining technique will be useful in specimen machining to evaluate changes in mechanical properties of materials harvested in high-radioactive reactor. Also, it is expected that various types of specimens can be machining by applying the developed machining technique in the future.
        220.
        2022.10 구독 인증기관·개인회원 무료
        Organic scintillator is easy to manufacture a large size and the fluorescence decay time is short. However, it is not suitable for gamma measurement because it is composed of a low atomic number material. Organic scintillation detectors are widely used to check the presence or absence of radiation. The fluorescence of organic scintillators is produced by transitions between the energy levels of single molecules. In this study, an organic scintillator development study was conducted for use in gamma measurement, alternative materials for secondary solute used in basic organic scintillators were investigated, and the availability of alternative materials, detection characteristics, and neutron/gamma identification tests were performed. In other words, a secondary solute showing an improved energy transfer rate than the existing material was reported, and the performance was evaluated. 7-Diethylamino -4-methylcoumarin (DMC), selected as an alternative material, is a benzopyrone derivative in the form of colorless crystals, has high fluorescence and high quantum yield in the visible region, and has excellent light stability. In addition, it has a large Stokes shift characteristic, and solubility in solvent is good. Through this study, it was analyzed that the absorption wavelength range of DMC coincided with the emission wavelength range of PPO, which is the primary solute. Through this study, it was confirmed that the optimal concentration of DMC was 0.04wt%. As a result of performing gamma and neutron measurement tests using a DMC-based liquid scintillator, it showed good performance (FOM=1.42) compared to a commercial liquid scintillator. Therefore, the possibility of use as a secondary solute was demonstrated. Based on this, if studies on changes in the composition of secondary solute or the use of nanoparticles are conducted, it will be possible to manufacture and utilize a scintillator with improved efficiency compared to the existing scintillator.