Locations In South Korea Research Articles

Climate change impacts on Allium crop production: Insights from long-term observations in South Korea

Climate change is an imminent threat, particularly affecting agricultural productivity, which relies heavily on weather conditions. Understanding the specific impacts of climate change on key crops is crucial for developing effective adaptation strategies to ensure food security. The growth patterns of onions and garlic were observed at over ten different locations in South Korea, and the yield data from the past 40 years were analyzed. The yield was significantly correlated with temperature and strongly affected by the frequent and unexpected patterns of precipitation. The increase in mean temperature during winter and the spatial and temporal concentration of precipitation are expected to be the most influential factors for Allium crop production in the future. In addition, the yields of onions and garlic can serve as good indicators for predicting the impacts of weather on agricultural productivity, given their extended cultivation periods and significant correlations with temperature and precipitation. As climate change scenarios become available, the results of this study can serve as a basis for predicting changes in agricultural production in the future and identifying opportunities to adapt cultivation systems for food security.

Microbiome profile of South Korean vector mosquitoes

This research offers a comprehensive exploration of the microbial communities associated with vector mosquitoes from South Korea. Aedes albopictus, Anopheles sinensis, and Culex molestus are vectors of pathogens, and understanding the intricacies of their microbiome profile is paramount for unraveling their roles in disease transmission dynamics. In this study, we characterized the microbiome of the midguts of adult female vector mosquitoes collected from different locations in South Korea. After DNA extraction from dissected mosquito midguts, we used the Illumina MiSeq next-generation sequencing to obtain sequences spanning the V4 hypervariable region of the bacteria 16S rRNA. Morphological and molecular characterization using 506-bp mitochondrial 16S rRNA was used to identify the mosquito species before amplicon sequencing. Across the three vector mosquitoes surveyed, 21 bacteria genera belonging to 20 families and 5 phyla were discovered. Proteobacteria and Bacteriodota were the major phyla of bacteria associated with the three mosquito species. There were significant differences in the gut microbiome genera composition between the species and little variation in the gut microbiome between individuals of the same mosquito species. Wolbachia is the most dominant genus in Aedes while Aeromonas, Acinetobacter, and unassigned taxa are the most common in An. sinensis. In addition to that, Chromobacterium, Chryseobacterium, and Aeromonas are dominant in Cx. molestus. This study sheds light on the complex interactions between mosquitoes and their microbiome, revealing potential implications for vector competence, disease transmission, and vector control strategies.

Analysis of microplastics distributed in the environment: Case studies in South Korea

The massive production and extensive distribution of microplastics, stemming from postconsumer plastics, have become problematic for the environment and human health. Various studies have reported the hazardous potential and toxicity of microplastics in living organisms, including animals and humans. As a precautionary measure to protect them from microplastic exposure, significant efforts have been made to analyze the distribution of microplastics in the environment. However, each research group individually examined the microplastic distribution in a specific location. Consequently, there is a lack of information regarding the presence of microplastics in wider district units, such as cities and across the nation. In this study, an overview of various case studies in South Korea is provided by discussing the presence and concentration of microplastics in South Korea and examining the reports and research articles on the analysis of microplastic distributions in different locations in South Korea. The current sampling and analysis methods used for microplastic distribution studies were also summarized, along with their technical challenges. The possible sources of primary and secondary microplastics were also discussed to determine the original plastic types of microplastics derived from industries and households.

Serpentinization and potential Ni‐Cr mineralization of the Andong ultramafic block in South Korea

AbstractSmall‐ to medium‐sized serpentinized ultramafic blocks have been found in several locations in South Korea. Ultramafic‐hosted serpentinization, described as a major hydrothermal process that affects the lithospheric mantle, is known to play a key role in mass fluxes enhanced by multiple fluid–rock interactions that ultimately lead to the formation of hydrothermal mineralization and natural hydrogen production. In this study, we attempted to interpret the hydrothermal alteration and associated Ni‐Cr mineralization of the Andong serpentinized ultramafic block (ASUB). Based on the mineralogical and geochemical studies, the serpentinites and serpentinized ultramafic rocks of the ASUB are interpreted to be derived from mantle peridotite. It shows the dunite, lherzolite, and wehrlite compositions which are mainly composed of olivine and pyroxene. Hydrothermal alteration transformed the ultramafic rock into serpentinitic rock, resulting in changes in rock textures from the parent rock (plutonic texture) to moderately altered rock (pseudomorphic porphyritic texture) and strongly altered rock (pseudomorphic fine grained texture) with mineralogical changes. Serpentinization and Ni‐Cr mineralization do not show any relationship. Considering the reported crystallization age of the parental rock (222 Ma) and measured age (214–187 Ma) of the granites intruded into the ASUB, the source magma responsible for the final hydrothermal event including serpentinization is inferred to be the Late Triassic to Early Jurassic granitic pluton. The ASUB might have formed due to the ascent of a mantle plume along the extensional regime (i.e., rift) in the supra‐subduction zone (SSZ), rather than in ophiolite‐related mid‐oceanic ridges or abyssal environments, which are identified in many places. Ni‐Cr mineralization, with the close association of pentlandite, pyrrhotite, and Cr‐spinel, likely resulted from co‐precipitation and dissemination during the crystallization of the parent peridotitic magma derived from the mantle.

Multivariate Analysis among Marker Compounds, Environmental Factors, and Fruit Quality of Schisandra chinensis at Different Locations in South Korea.

This study aimed to investigate the correlation among the contents of marker compounds, growth characteristics, and environmental factors of Schisandra chinensis fruits across South Korea. The fruits were collected from 36 cultivation sites in 28 regions across the country. We investigated nine growth characteristics, twelve soil physicochemical properties, eight meteorological data, and three marker compounds in this study. We optimized and validated an optimized method for quantifying marker compounds using UPLC and performed correlation analysis among the contents of marker compounds, growth characteristics, and environmental factors. The UPLC-UV method for analyzing marker compounds was validated by measuring linearity, LOD, LOQ, precision, and accuracy. The marker compounds were negatively correlated with the fruit size and sugar contents, and growth characteristics were negatively correlated with some physicochemical properties of the soil. The results of this study can be used as basic data for the standard cultural practices and quality control of S. chinensis fruits.

Pavement freezing depth estimation using hybrid deep-learning models

Predicting pavement temperature by depth is crucial for road design, analysis, and maintenance. However, current methods predominantly utilize regression and/or open-form solutions focusing on highways. Additionally, most machine-learning models focus on asphalt layers and do not extend to deeper pavement layers. Therefore, this study provides deep-learning models using weather parameters to predict pavement temperature from surface to sublayers and estimate pavement freezing depth for developing massive apartment complexes. Temperature-by-depth data collected from thin pavements from three locations in South Korea were used. Comparative analyses of long short-term memory (LSTM), convolutional neural network-LSTM (CNN-LSTM), and convolutional LSTM were performed. Results showed that CNN-LSTM model performed better with coefficients of determination ( R2) of 0.965, 0.987, and 0.981. Additionally, the CNN-LSTM predicted freezing depth with 0.3%–13.1% error margins outperforming the LSTM, Aldrich’s, and Korean Ministry of Transport approaches. The proposed approach shows that deep-learning models better estimate the freezing depth of pavements than existing approaches.

Formation uplift analysis during geological CO2-Storage using the Gaussian pressure transient method: Krechba (Algeria) validation and South Korean case studies

The Paris Climate Agreement of 2015, along with the commitments in the South Korean 2050 Carbon-Neutral Scenario, highlights the importance of carbon capture and storage (CCS) to counter advancing global warming. During CCS, carbon-dioxide enriched fluid is injected into a geological formation, which causes pore pressure increases. The CCS must occur safe and stable, which requires geomechanical modeling to analyze the effects of formation uplift and subsidence. In this study, surface uplift and subsidence were predicted with a recently developed Gaussian pressure transient (GPT) method, in advance of the anticipated CO2-injection schemes to ensure a secure storage process. The GPT-results were first validated against field observations obtained from the In Salah CCS-site (Algeria). Next, the GPT-method was applied to two potential CCS target locations in South Korea: (1) the Pohang basin, and (2) the Donghae gas reservoir. Maximum uplifts of 25.42 and 32.55 mm, respectively, were estimated for each location. In addition, the effect of installing a relief well to mitigate the uplift was studied. Subsidence was estimated around the relief well due to production. The presence of the relief well aided the mitigation of both uplift and subsidence. Our study shows that preliminary analysis of uplift and subsidence of potential CCS-sites is possible with the GPT-method. In addition, it was shown that installing (one or more) relief well(s) for the purpose of mitigating the severe uplift caused by injection is feasible.

An Integrative Process-Based Model for Biomass and Yield Estimation of Hardneck Garlic (Allium sativum).

We introduce an integrative process-based crop model for garlic (Allium sativum). Building on our previous model that simulated key phenological, morphological, and physiological features of a garlic plant, the new garlic model provides comprehensive and integrative estimations of biomass accumulation and yield formation under diverse environmental conditions. This model also showcases an application of Cropbox to develop a comprehensive crop model. Cropbox is a crop modeling framework featuring declarative modeling language and a unified simulation interface for building and improving crop models. Using Cropbox, we first evaluated the model performance against three datasets with an emphasis on biomass and yield measured under different environmental conditions and growing seasons. We then applied the model to simulate optimal planting dates under future climate conditions for assessing climate adaptation strategies between two contrasting locations in South Korea: the current growing region (Gosan, Jeju) and an unfavorable cold winter region (Chuncheon, Gangwon). The model simulated the growth and development of a southern-type cultivar (Namdo, ND) reasonably well. Under Representative Concentration Pathway (RCP) scenarios, an overall delay in optimal planting date from a week to a month, and a slight increase in potential yield were expected in Gosan. Expansion of growing region to northern area including Chuncheon was expected due to mild winter temperatures in the future and may allow ND cultivar production in more regions. The predicted optimal planting date in the new region was similar to the current growing region that favors early fall planting. Our new integrative garlic model provides mechanistic, process-based crop responses to environmental cues and can be useful for assessing climate impacts and identifying crop specific climate adaptation strategies for the future.

Wind-driven rain exposure on building envelopes taking into account frequency distribution and correlation with different wall orientations

Excessive moisture inside building envelopes makes them vulnerable to moisture damages such as mould, algae growth, rot, corrosion, weathering, fading, etc. One of the main moisture sources for building envelopes is wind-driven rain (WDR). This paper characterizes the WDR for twenty-two locations in South Korea based on hourly measured weather data for 20 years and an artificial typical year from Meteonorm®. This study determines a wind-driven rain reference year using a semi-empirical method, taking into account the frequency of occurrence of the WDR and the correlation between the different wall orientations. The annual amount of the WDR shows a significant range from 125.4 kg/(m2∙a) to 904.4 kg/(m2∙a) with the individual prevailing orientations by location in South Korea. The deviations of the WDRs determined by the wind-driven rain reference year and the annual mean wind-driven rain can be characterized in two groups in terms of the amount and the distribution of the WDR. The first group has a characteristic that only the amount is changed while keeping the distribution across the wall orientations. The second group shows that the amount and the distribution are changing together. The wind-driven reference year can characterize the WDR by selecting and combining the most representative periods from the long-term measurements. By contrast, the artificial typical years from Meteonorm® hardly show any similar characteristics of the WDR determined with the long-term measured weather data.

Influence of genetic and environmental factors on the contents of carotenoids and phenolic acids in red pepper fruits (Capsicum annuum L.)

Red pepper is enriched in antioxidant components, such as carotenoids, phenolic compounds, and vitamins. In this study, we investigated the natural variability in the content of carotenoids and phenolic acids in 11 red pepper cultivars grown in two locations in South Korea during 2016, 2017, and 2018. Seven carotenoids and six phenolic acids, including soluble and insoluble forms, were detected in the red fruit pericarps. The major carotenoids were β-carotene (40%) and capsanthin (20%). The content of insoluble phenolic acids was higher than that of soluble phenolic acids because of the large amount of insoluble p-coumaric acid. The statistical analysis of combined data showed significant differences among varieties, locations, and years for most of the measured components. The results from variance component analysis indicated that the effects of location, year and the interaction of location and year mainly accounted for the variation in carotenoids, whereas variations in phenolic acid content were attributed to year and variety. In addition, the results of principal component analysis and orthogonal partial least-squares discriminant showed that carotenoids were well discriminated by location and year, whereas phenolic acids were distinctively separated only by year. The data from this study could explain the natural variation in the content of carotenoids and phenolic acids in red pepper fruits by genotype and environment.

Performance Assessment of Global Horizontal Irradiance Models in All-Sky Conditions

Solar irradiance models contribute to mitigating the lack of measurement data at a ground station. Conventionally, the models relied on physical calculations or empirical correlations. Recently, machine learning as a sophisticated statistical method has gained popularity due to its accuracy and potential. While some studies compared machine learning models with other models, a study has not yet been performed that compares them side-by-side to assess their performance using the same datasets in different locations. Therefore, this study aims to evaluate the accuracy of three representative models for estimating solar irradiance using atmospheric variables measurement and cloud amount derived from satellite images as the input parameters. Based on its applicability and performance, this study selected the fast all-sky radiation model for solar applications (FARMS) derived from the radiative transfer approach, the Hammer model that simplified atmospheric correlation, and the long short-term memory (LSTM) model specialized in sequential datasets. Global horizontal irradiance (GHI) data were modeled for five distinct locations in South Korea and compared with hourly measurement data of two years to yield the error metrics. When identical input parameters were used, LSTM outperformed the FARMS and the Hammer model in terms of relative root mean square difference (rRMSD) and relative mean bias difference (rMBD). Training an LSTM model using the input parameters of FARMS, such as ozone, nitrogen, and precipitable water, yielded more accurate results than using the Hammer model. The result shows unbiased and accurate estimation with an rRMSD and rMBD of 23.72% and 0.14%, respectively. Conversely, the FARMS has a faster processing speed and does not require significant data to make a fair estimation.

Rain Attenuation Scaling in South Korea: Experimental Results and Artificial Neural Network

Scaling rain attenuation parameters will significantly benefit the quick monitoring of rain attenuation in a particular channel with previously known results or in situ setup attenuation measurements. Most of the rain attenuation scaling techniques have been derived for slant links. In this study, we also applied frequency and polarization scaling techniques for terrestrial link applications. We collected real measured datasets from research paper publications and examined those datasets using International Telecommunication Union-Radiocommunication sector (ITU-R) models (P.530-17, P.618-13). Our analyzed results show that existing long-term frequency and polarization scaling rain attenuation models (ITU-R P.618-13 for slant links and ITU-R P.530-17 for terrestrial links) show reduced performance for frequency and polarization scaling measured locations in South Korea. Hence, we proposed a new scaling technique using artificial neural networks from the measured rain attenuation data of slant and terrestrial links in South Korea. The experimental results confirm that the proposed Artificial Neural Network (ANN)-based scaling model shows satisfactory performance to predict attenuation for frequency and vertical polarization scaling.

Quantitative analysis of polyethylene terephthalate and polycarbonate microplastics in sediment collected from South Korea, Japan and the USA

Microplastics (MPs) have emerged as contaminants of public health and environmental concern. Although studies have reported the occurrence of MPs in sediment, quantitative determination of polyethylene terephthalate (PET) and polycarbonate (PC) concentrations is limited. In this study, marine coastal and freshwater sediment collected from various locations in South Korea, Japan and the United States were analyzed for PET and PC MPs using a depolymerization method of sample preparation followed by high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) detection. PET MPs were found in surface sediments from South Korea (n = 20), Japan (n = 4) and the United States (n = 43) at concentrations (dry weight) in the ranges of <MQL-13,000,000 ng/g (median: 6600 ng/g), 3600–5400 ng/g (4400 ng/g) and <MQL-10,000 ng/g (<MQL), respectively. Similarly, PC MPs were found in the concentration ranges of <MQL-140,000 ng/g (median: 290 ng/g, South Korea), 150–510 ng/g (100 ng/g, Japan) and <MQL-110,000 ng/g (160 ng/g, the United States). Spatial analysis of concentrations of PET and PC MPs in sediment from Lake Shihwa watershed in South Korea showed a decreasing trend with increasing distance from inland point source areas (Ansan industrial area). No distinct vertical profiles were recorded for PET or PC MPs in sediment cores collected from Tokyo Bay (Japan) or inland lakes in Michigan (the United States). The measured concentrations of MPs in sediment provide baseline data to evaluate future trends and for ecological risk assessment.

Influence of electrolytic and crevice corrosion on mechanical resistance of porcelain insulators

Porcelain insulators are widely used in transmission lines; however, their durability and considerable overall maintenance cost have become problems over the years. In this work, porcelain insulators were collected from various locations in South Korea and classified according to their length of service. Mechanical and electrical load tests were performed, and the failure load and damaged region were recorded for each specimen. The fast degradation of the pin in porcelain insulators exceeding 50 years in operation was notable because there was no pin breakage among the samples in service for less than 50 years. Moreover, the failure of 73.68% of all porcelain insulators in service for 54 years occurred in the pin. The average failure load of these samples was 14% lower than that of samples in use for 45 years. To confirm the pin’s deterioration mechanism over time, a mechanical analysis of the reduction in the pin cross-section was performed using the finite element analysis method. Applied loads of 45, 75, and 95 kN resulted in stresses of 170, 285, and 350 MPa, respectively, in the bottom half part of the pin exposed to air. To calculate the stresses due to corrosion, the model was redrawn considering diameter reductions of 0.6, 1.2, 1.8, and 2.4 mm. The stress fields were found to considerably affect the corroded zone even in the case of the sample with a 0.6-mm reduction in diameter. Accordingly, a novel degradation mechanism is proposed in this study. Previous studies that focused on the critical areas of the porcelain insulator found that the exposed pin side was easily damaged by the external load. The current findings revealing an unfamiliar porcelain deterioration mechanism may aid in the formulation of a better design to mitigate the problems described above.

Comparison of the seed nutritional composition between conventional varieties and transgenic soybean overexpressing Physaria FAD3-1.

BACKGROUND PfFAD3 transgenic soybean expressing omega‐3 fatty acid desaturase 3 of Physaria produces increased level of α‐linolenic acid in seed. Composition data of non‐transgenic conventional varieties is important in the safety assessment of the genetically‐modified (GM) crops in the context of the natural variation.RESULTSThe natural variation was characterized in seed composition of 13 Korean soybean varieties grown in three locations in South Korea for 2 years. Univariate analysis of combined data showed significant differences by variety and cultivation environment for proximates, minerals, anti‐nutrients, and fatty acids. Percent variability analysis demonstrated that genotype, environment and the interaction of environment with genotype contributed to soybean seed compositions. Principal component analysis and orthogonal projections to latent structure discriminant analysis indicated that significant variance in compositions was attributable to location and cultivation year. The composition of three PfFAD3 soybean lines for proximates, minerals, anti‐nutrients, and fatty acids was compared to a non‐transgenic commercial comparator (Kwangankong, KA), and three non‐transgenic commercial varieties grown at two sites in South Korea. Only linoleic and linolenic acids significantly differed in PfFAD3‐1 lines compared to KA, which were expected changes by the introduction of the PfFAD3‐1 trait in KA.CONCLUSIONGenotype, environment, and the interaction of environment with genotype contributed to compositional variability in soybean. PfFAD3‐1 soybean is equivalent to the conventional varieties with respect to these components. © 2020 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Quantitative Analysis Methods of Chloride Deposition on Silver for Atmospheric Corrosion Monitoring in South Korea

The chloride deposition rate is one of critical factors affecting the atmospheric corrosion of metals, which can be monitored by exposing Ag specimens and analyzing their surfaces using various ways. Although a coulometric reduction method can provide an absolute chloride deposition rate, new and alternative methods can be pursued, i.e., methods using typical surface analysis tools (scanning electron microscopy-energy dispersive x-ray spectroscopy [SEM-EDS], x-ray diffraction [XRD], and x-ray photoelectron spectroscopy [XPS]). As the surface analysis tools can only provide relative values, a correlation between the coulometric reduction and surface analyses should be developed. To develop the correlation between them, Ag specimens were prepared by exposing them to the atmosphere at 12 locations in South Korea for one year. Surface analysis of retrieved Ag specimens yielded correlations for the chloride deposition rates between the coulometric reduction method and typical surface analysis tools. Each correlation showed a fairly linear relationship, especially ones obtained from SEM-EDS and XPS. The developed correlations can be used when estimating the chloride deposition rate by using surface analysis tools as an alternative to the coulometric reduction method.

Disruption of Firmicutes and Actinobacteria abundance in tomato rhizosphere causes the incidence of bacterial wilt disease

Enrichment of protective microbiota in the rhizosphere facilitates disease suppression. However, how the disruption of protective rhizobacteria affects disease suppression is largely unknown. Here, we analyzed the rhizosphere microbial community of a healthy and diseased tomato plant grown <30-cm apart in a greenhouse at three different locations in South Korea. The abundance of Gram-positive Actinobacteria and Firmicutes phyla was lower in diseased rhizosphere soil (DRS) than in healthy rhizosphere soil (HRS) without changes in the causative Ralstonia solanacearum population. Artificial disruption of Gram-positive bacteria in HRS using 500-μg/mL vancomycin increased bacterial wilt occurrence in tomato. To identify HRS-specific and plant-protective Gram-positive bacteria species, Brevibacterium frigoritolerans HRS1, Bacillus niacini HRS2, Solibacillus silvestris HRS3, and Bacillus luciferensis HRS4 were selected from among 326 heat-stable culturable bacteria isolates. These four strains did not directly antagonize R. solanacearum but activated plant immunity. A synthetic community comprising these four strains displayed greater immune activation against R. solanacearum and extended plant protection by 4 more days in comparison with each individual strain. Overall, our results demonstrate for the first time that dysbiosis of the protective Gram-positive bacterial community in DRS promotes the incidence of disease.

Ground source heat pump (GSHP) systems for horticulture greenhouses adjacent to highway interchanges: A case study in South Korea

Although fuel-burning systems have long been used as climate control tools in greenhouses, their energy efficiency remains low, causing hikes in operation costs and sacrificing the quality and quantity of horticulture products, not to mention emitting greenhouse gases. To address these issues, a new geothermal energy supply model was developed for greenhouses close to highway Interchanges (ICs) or Junctions (JCTs). This paper presents a comprehensive effort made with field tests and simulations to validate the proposed model at various locations in South Korea. First, a Ground Source Heat Pump (GSHP) system – a central component of the model - was installed in a greenhouse and its efficiency was evaluated and compared with other fuel-burning systems. Second, cost-benefit analyses were carried out to assess whether the proposed model was investible under four possible operation scenarios. Third, the model was simulated at twenty-four ICs and JCTs along 9 highway routes to illustrate the beneficial effects of the model’s scaled-up deployment. The proposed model yielded the highest net income when a GSHP system was running at full capacity for heating and cooling. The payback periods of the model deployed at multiple sites (24 ICs and JCTs) were fewer than two years relative to AC/boiler systems. These findings indicate that the proposed model can be worthy of investment if it is appropriately operated and deployed in the field. Existing rules and policies could be used to help promote the implementation of the model.

The botanical origin and antioxidant, anti-BACE1 and antiproliferative properties of bee pollen from different regions of South Korea

BackgroundBee pollen (BP) has been used as a traditional medicine and food diet additive due to its nutritional and biological properties. The potential biological properties of bee pollen vary greatly with the botanical and geographical origin of the pollen grains. This study was conducted to characterize the botanical origin and assess the antioxidant effects of ethanol extracts of 18 different bee pollen (EBP) samples from 16 locations in South Korea and their inhibitory activities on human β-amyloid precursor cleavage enzyme (BACE1), acetylcholinesterase (AChE), human intestinal bacteria, and 5 cancer cell lines.MethodsThe botanical origin and classification of each BP sample was evaluated using palynological analysis by observing microscope slides. We measured the biological properties, including antioxidant capacity, inhibitory activities against human BACE1, and AChE, and antiproliferative activities toward five cancer cell lines, of the 18 EBPs. In addition, the growth inhibitory activities on four harmful intestinal bacteria, six lactic acid-producing bacteria, two nonpathogenic bacteria, and an acidulating bacterium were also assessed.ResultsFour samples (BP3, BP4, BP13 and BP15) were found to be monofloral and presented four dominant pollen types: Quercus palustris, Actinidia arguta, Robinia pseudoacacia, and Amygdalus persica. One sample (BP12) was found to be bifloral, and the remaining samples were considered to be heterofloral. Sixteen samples showed potent antioxidant activities with EC50 from 292.0 to 673.9 μg mL− 1. Fourteen samples presented potent inhibitory activity against human BACE1 with EC50 from 236.0 to 881.1 μg mL− 1. All samples showed antiproliferative activity toward the cancer cell lines PC-3, MCF-7, A549, NCI-H727 and AGS with IC50 from 2.7 to 14.4 mg mL− 1, 0.9 to 12.7 mg mL− 1, 5.0 to > 25 mg mL− 1, 2.7 to 17.7 mg mL− 1, and 2.4 to 8.7 mg mL− 1, respectively. In addition, total phenol and flavonoid contents had no direct correlation with antioxidant, anti-human BACE1, or antiproliferative activities.ConclusionFundamentally, Korean bee pollen-derived preparations could be considered a nutritional addition to food to prevent various diseases related to free radicals, neurodegenerative problems, and cancers. The botanical and geographical origins of pollen grains could help to establish quality control standards for bee pollen consumption and industrial production.

Long-term surveillance of bat coronaviruses in Korea: Diversity and distribution pattern.

Bats harbour diverse coronaviruses (CoVs), some of which are associated with zoonotic infections, as well as inter‐species transmission. In this study, a total of 512 bat faecal samples from the bat habitats at different geographical locations in South Korea were investigated between 2016 and 2019. Seventy‐eight samples were positive for coronaviruses (15.2%), comprising 68 alphacoronaviruses (13.3%) and 10 betacoronaviruses (2.0%). The positive rates tended to increase during the awakening (April) period. Notably, betacoronaviruses were only found in the site where Rhinolophus ferrumequinum was the major species of bats, and were related to SARS‐ and MERS‐related CoVs identified in China and South Korea, respectively. No betacoronaviruses were closely related to SARS‐CoV‐2 in this study. Alphacoronaviruses were detected in the sites where Hypsugo alaschanicus, Miniopterus fuliginosus, Miniopterus schreibersii, Rhinolophus ferrumequinum, Myotis bombinus, Myotis macrodactylus and Myotis petax were found to be the major bat species. Furthermore, alphacoronaviruses had higher genetic diversity than betacoronaviruses and had a wider distribution in Korea. Considering that different bat species are co‐roosting in crowded conditions in the same habitat, the diverse coronaviruses in Korean bats are likely to undergo cross‐species transmission events due to the richness in host species. Therefore, continuous monitoring should be performed, especially at the awakening time of the hibernating bats in the habitats where diverse bat species co‐roost, to better understand the evolution of coronaviruses in bats.