The corrosivity of molten salt presents a major challenge for the commercialization of molten salt reactors, which utilize molten salt as both fuel and coolant. To protect structural materials of molten salt reactors, minimizing moisture—the primary source of corrosion—is crucial, necessitating precise moisture concentration measurements. This study examines the role of an inert gas atmosphere in analyzing moisture in molten chloride salts. Four chloride salts with different hygroscopic properties (NaCl, KCl, MgCl2 and ZnCl2) were tested. Each was analyzed in three states: as-received and dried by heating for 6 and 12 hours. Karl Fischer titration was employed to measure the moisture concentrations in salts under both air and an argon-filled glove box. Results showed consistently lower and more stable moisture concentrations in the inert atmosphere, highlighting the necessity of an argon environment for accurate moisture analysis in molten salts.
본 연구에서는 국내에서 처음 발견된 Aulacophoroides hoffmanni (Takahashi, 1937)를 최초로 보고한다. 2024년 야외조사에서 한국의 서부 2개 지역의 등나무(Wisteria floribunda (Willdenow))에서 심각한 피해를 주고 있는 A. hoffmanni를 확인하였다. 무시성충의 상세한 형태 기재와 계측값을 제시하였으며, 생체 및 슬라이드 표본 사진을 포함하였다. 이 종은 등나무에 심각한 피해를 주고 있어 관상용 등나무의 주요 해충이 될 것으로 예상된다.
The role of the gut microbiota in colorectal cancer (CRC) development has garnered attention, highlighting probiotics as potential adjuncts in CRC prevention and treatment. In recent years, probiotics and their derivatives have demonstrated mechanisms that may contribute to anticancer properties. This study investigates the cytotoxic effects of Bifidobacterium bifidum KCTC 3357, Lacticaseibacillus rhamnosus KCTC 5033, Limosilactobacillus reuteri VA 103, Bacillus galactosidilyticus VA 107, and Lactococcus taiwanensis VE101 on CT-26 mouse colon carcinoma cells using live cells, heat-killed cells (paraprobiotics), and cell-free supernatants (CFS, postbiotics) through an MTT assay. The results indicate that live bacterial strains, such as KCTC 3357, VA 103, and VA 107, promoted CT-26 cell viability, while heat-killed cells and CFS exhibited dose-dependent cytotoxicity. Inactivated forms of KCTC 3357 and VE 101, as well as CFS at 10 mg/mL concentration of KCTC 5033, VA 103, and VE 101, showed the strongest antiproliferative effects. These findings suggest that non-viable probiotic derivatives, such as paraprobiotics and postbiotics, offer promising therapeutic potential for CRC, providing a safer and more stable alternative to live probiotics. However, further research is required to explore their mechanisms of action, in vivo efficacy, and potential clinical applications.
This study explored factors affecting variability in second language (L2) learning motivation among Korean university students and how they appraised their L2 learning experience. In this study, 85 undergraduate students majoring in English or English education from three universities in Seoul, South Korea, reflected on their past English learning experience. They drew a motigraph and wrote a retrospective reflection essay covering their English learning that spanned over ten years. Researchers divided participants into two groups: a high variability (HV) group and a low variability (LV) group. Data were analyzed using open, axial, and selective coding. Findings suggest thncontextual factors such as the learning method, atmosphere, and situation were main (de)motivational factors for the HV group. In contrast, the LV group was (de)motivated by intrapersonal factors, including the learning context appraisal. These results imply that visualizing long and short-term goals and positive appraisal of the L2 learning experience can help L2 learners maintain a stable pattern in L2 learning motivation.
Galaxy evolution studies require the measurement of the physical properties of galaxies at different redshifts. In this work, we build supervised machine learning models to predict the redshift and physical properties (gas-phase metallicity, stellar mass, and star formation rate) of star-forming galaxies from the broad-band and medium-band photometry covering optical to near-infrared wavelengths, and present an evaluation of the model performance. Using 55 magnitudes and colors as input features, the optimized model can predict the galaxy redshift with an accuracy of σ(Δz/1+z) = 0.008 for a redshift range of z < 0.4. The gas-phase metallicity [12 + log(O/H)], stellar mass [log(Mstar)], and star formation rate [log(SFR)] can be predicted with the accuracies of σNMAD = 0.081, 0.068, and 0.19 dex, respectively. When magnitude errors are included, the scatter in the predicted values increases, and the range of predicted values decreases, leading to biased predictions. Near-infrared magnitudes and colors (H, K, and H −K), along with optical colors in the blue wavelengths (m425–m450), are found to play important roles in the parameter prediction. Additionally, the number of input features is critical for ensuring good performance of the machine learning model. These results align with the underlying scaling relations between physical parameters for star-forming galaxies, demonstrating the potential of using medium-band surveys to study galaxy scaling relations with large sample of galaxies.
Background: In patients with low back pain (LBP), weakened core muscles and impaired proprioception contribute to decreased spinal stability and LBP recurrence. Objectives: To investigate the effects of abdominal bracing exercises (BE) and kinetic link training (BEKLT) on pain, balance, and proprioception in LBP patients. Design: Randomized controlled trial. Methods: Sixteen adults with LBP were randomly assigned to a BE group or a BEKLT group. Both groups completed a four-week intervention (three sessions per week). Pain was assessed using the visual analog scale (VAS), proprioception with the lumbar reposition sense test, and balance with the BT4 system. Results: Both groups showed significant reductions in VAS and proprioception error (P<.05), with no inter-group differences. In dynamic balance (limits of stability), the BE group improved in rearward, left, and right angles, while the BEKLT group improved in forward, rearward, and left angles (P<.05). A significant difference was observed in the forward leaning angle between groups (P<.05). For static balance, both groups showed significant reductions in trace length and C90 area (P<.05), with no inter-group differences. Conclusion: The findings suggest that both BE and BEKLT are effective interventions for reducing pain and improving proprioception and balance in LBP, with BEKLT providing additional benefits for dynamic balance.
The transportation of spent nuclear fuel between management stages is expected, and the transportation workers may be exposed to radiation. When transporting spent nuclear fuel, the ALARA principle must be observed for the workers. The objective of this study is to assess a radiation dose for workers transporting spent nuclear fuel using metal overpacks. For this objective, the cask to be handled was selected and the radiation source term was set. Then, the radiation exposure scenario for the transportation workers was defined. Finally, the dose rates for each location of operation were assessed using Monte Carlo simulations, and collective doses were derived for each operation considering the radiation exposure scenario. Each worker performed 11 operations to transport spent nuclear fuel to other facilities and was exposed to a total of 1.138 man-mSv. The operation of removing the bottom shield ring resulted in the highest radiation exposure at 0.503 man-mSv. In contrast, the operation of installing the impact limiter resulted in the lowest radiation exposure at 0.0009 man-mSv. The results of this study can be used to strengthen radiation protection measures for workers transporting spent nuclear fuel in dry storage facilities using metal overpacks.
식품첨가물 카민과 코치닐 추출물은 붉은 색을 띄는 색 소로, 주로 코치닐 곤충에서 유래하며 카민산이 주요 성 분으로 사탕, 어묵과 같이 널리 소비되는 식품에 일반적 으로 사용되고 있다. 최근 카민산은 특정 단백질과 관련된 알레르기 반응과 연관이 있는 것으로 보고되고 있다. 본 연 구는 highperformance liquid chromatography with a diode array detector (HPLC-DAD)와 C18 UG120 컬럼을 사용하 여 카민산을 정량시험법을 개발하고 밸리데이션을 수행하 였다. HPLC 최적 분석조건은 이동상 (A)물-트리플루오로 아세트산(trifluoroacetic acid, TFA) 0.1% 및 (B)아세토니트 릴-TFA 0.1%, 유속 1.0 mL/min, 컬럼온도 30oC에서 수행하 였으며, 검량선(0.2-50 mg/L) 범위에서 우수한 결정계수 (r2≥0.9999)를 보였다. 또한, liquid chromatography-tandem mass spectrometry (LC-MS/MS)를 활용한 정성 분석을 통해 limit of detection (LOD) 0.05 mg/k, limit of quantification (LOQ) 0.15 mg/kg을 보였다. 또한, 일내 및 일간 밸리데이 션에서 정확도(87.3-97.1%, 회수율)와 정밀도(0.48-8.90%, 상대표준편차)이었으며, 측정 불확도 또한 추정하였다. 개 발된 분석법은 다양한 식품 유형에 적용 가능하며, 카민과 코치닐 추출물의 모니터링을 통해 카민산과 관련된 잠재적 인 문제가능성을 확인하는 데 활용될 수 있을 것으로 사료 된다.
We analyzed the mineral composition of compacted calcium bentonite (GJ-I) and uncompressed sodium bentonite (MX80), both of which were exposed for two years in the YS03 borehole. The YS03 borehole is characterized by a high concentration of anaerobic microorganisms, including sulfate-reducing bacteria, elevated levels of hydrogen sulfide, and high pH conditions. The compacted Ca bentonite showed minimal alteration, with a small amount of new magnetite formation. However, an X-ray diffraction (XRD) analysis revealed that the uncompressed Na bentonite underwent a complete transformation from montmorillonite to muscovite, goethite, and magnetite. Therefore, it is suspected that the compactness of the bentonite significantly impacts the rate of alteration. Furthermore, an X-ray fluorescence (XRF) analysis demonstrated a marked increase in iron oxide in the Na bentonite, whereas key elements of montmorillonite such as alumina (Al2O3), silica (SiO2), and magnesium oxide (MgO) showed substantial decreases. The presumed cause of the alteration in the uncompressed MX80 bentonite is the presence of Fe cations coupled with a high pH environment. We believe that Fe cations, which were likely released from the corrosion of cast iron, played a significant role in altering the montmorillonite lattice.
The increase in radioactive waste increased the demand for transportation to the disposal facility. Prior to transporting radioactive waste, confirming that the potential exposure is insignificant is crucial. Overland transportation risk assessment models were developed tailored to domestic characteristics. Dose assessment using this model requires selecting appropriate factors. However, users may struggle to derive appropriate values, leading to inaccuracies. Additionally, if assessment results show outliers, prioritizing factors for review can be challenging. Therefore, sensitivity analysis is necessary to prioritize factors for accurate assessment. In this study, sensitivity analysis was conducted on the on-link public risk assessment model factors for radioactive waste overland transportation. Initially, assessment models were analyzed by each detailed exposure scenario. Subsequently, uncertainty propagation-based sensitivity analysis methodology was applied. The default values for the assessment model factors were set, and sensitivity analysis was conducted based on road type for maximum individual and collective dose assessment models. For the maximum individual dose model, the distance to the samedirection vehicle was the most sensitive, whereas for the collective dose model, vehicle velocity was the most sensitive. The results of this study can be used as the basic data on radioactive waste transportation risk assessment in Korea in the future.
The irradiated large components in a nuclear power plant must perform dismantling after performing a lot of training through mockup, but this mockup training is different the realistic environment such as a high radiation environment. Therefore, to develop a training system deployed in eXtended Reality (XR) that mimics a realistic environment, a suitable training and evaluation processes need to be developed. The target components for the training system select reactor, reactor internal and steam generator, and the training work of dismantling processes select dismantling, packaging and dismantling support work by reviewing the dismantling process of each component for XR application. By analyzing the detailed process of the selected dismantling process, Virtual Reality (VR) and Augmented Reality (AR) application processes will be developed. The basic contents of training system present purpose, goal, period, and evaluation for training and the training contents develop the basic, improvement and intensified course by level. The basic model for evaluation develop 3 stages (reaction, training, behavior) and evaluation process present detail training contents, target and evaluation method, evaluation criteria by level. Additionally, the developed training course and evaluation models will be useful for worker training in dismantling process of nuclear power plant.
Rapid morphological changes in fish larvae during growth make adult classification criteria ineffective for identifying larval fishes. Therefore, species identification of fish larvae requires understanding morphological changes during growth stages within and between species. However, for many fish larvae, the lack of morphological trait information, along with physical damage or protein degradation that occurs during specimen collection and preservation in the wild, creates obstacles for morphology-based identification. A fish larva (10.0 mm SL) collected from the coastal waters of the western Korean Peninsula in August 2019 exhibited morphological characteristics and melanophore distribution patterns closely matching those of an unidentified species of the family Platycephalidae (sp.5). Its MT-CO1 amplicon sequences identified it as Cociella crocodilus, through genetic similarity with MT-CO1 reference sequences and phylogenetic analyses of related species. This study provides significant insights into the early life stages of Cociella crocodilus, marking the first identification of this species at the larval stage.
Wheat (Triticum aestivum L.), a significant cereal crop from the Gramineae family, serves as a vital source of protein, essential minerals, B-group vitamins, and dietary fiber. However, its productivity is often hindered by issues such as poor seed germination, which can adversely affect yield and crop quality. This study investigated the effects of different silicon concentrations and priming durations on wheat germination and seedling growth. Analysis of variance revealed that silicon treatment significantly influenced key parameters of germination and growth, including germination percentage (GP), germination index (GI), vigor index (VI), radicle length (RL), plumule length (PL), and seedling dry weight (SDW). Priming with silicon at a concentration of 1 mM resulted in notable improvements, increasing GP, GI, VI, RL, and PL by 10.6%, 65.5%, 29.4%, 18.6%, and 28.6%, respectively, after 6 hours of priming. Certain germination traits demonstrated strong positive correlations, particularly GP and GI (r = 0.96) and VI and RL (r = 0.94), after 4 hours of priming. These improvements in seed germination and seedling development may result from enhanced water uptake, stimulated cell division, and increased hydrolytic enzyme activity, which facilitate the mobilization of seed reserves and accelerate the growth of embryonic tissues.
곤충호텔은 곤충이 서식할 수 있도록 인위적으로 만든 구조 물로서 정원이나 텃밭 등 다양한 곳에서 활용되고 있다. 하지만 식생유형, 재료, 설치 방식 등에 따른 곤충 유입 효과에 대한 검증은 부족하며, 국가 또는 지역에 따른 곤충의 종류와 생육환 경이 다름에도 불구하고 곤충호텔에 대한 국내 연구는 전무한 실정이다. 따라서 본 연구에서는 국립수목원을 대상으로 구체적 인 식생유형 및 재료에 따른 유입 곤충 특성을 확인하고, 국내 실정에 맞는 효과적인 곤충호텔 설치 및 관리방안에 대한 기준 을 제시하고자 하였다. 조사구는 세 가지 식생유형(초지, 침엽수 림, 활엽수림)으로 구분하였으며, 각 식생의 조사구에 두 가지 재료(참나무, 잣나무)를 활용한 곤충호텔을 설치하였다. 조사는 2년동안(2022~2023) 진행되었으며, 매년 4~9월까지 주 1회 씩(총 48회) 곤충호텔의 유입 곤충을 직접 채집하였다. 곤충호 텔에서 채집된 곤충은 총 9목 46과 129종 3,057개체로, 2022 년에는 7목 34과 85종 1,750개체, 2023년에는 8목 35과 77종 1,307개체가 출현하였다. 연도별로 비교하면 1차년도에 유입 된 곤충의 개체수가 2차년도 보다 약 1.3배 많았고, 재료의 부식 에 따른 곤충의 구성도 달라졌다. 식생유형에 따라 구분하면 기간에 상관없이 활엽수림에서 유입 곤충이 가장 많았고, 침엽 수림에서 가장 적었다. 또한 재료에 따른 구분에서는 참나무가 잣나무보다 유입 곤충이 많았다. 참나무의 경우 유입 곤충의 연도별 차이가 적은 반면, 잣나무는 1년차에 비해 2년차에 약 2.3배 줄었다. 상관분석과 계층적 군집분석을 통한 곤충의 유입 특성은 식생유형보다는 재료의 영향이 큰 것으로 확인되었고, 식생유형만 비교했을 경우 초지에 비해 활엽수림과 침엽수림의 유사성이 높았다. 결론적으로 생물 다양성 증진을 목적으로 곤 충호텔을 설치하고자 한다면 초지나 활엽수림에 참나무 재료를 사용하는 것이 유리하며, 잣나무 재료를 이용한다면 1년 주기로 재료 교체가 필요할 것으로 판단된다. 하지만 특정 재료를 선호 하는 곤충의 기주특이성이 확인되었기 때문에 다양한 종류의 재료를 같이 사용하는 것도 하나의 방법이라고 사료된다. 향후 이를 기반으로 전시원에서 실질적으로 활용할 수 있는 곤충호텔 모델 개발로 확대해 나갈 예정이다.
국립수목원 전시원의 지속가능하고 친환경적인 관리를 위하 여 유기물 멀칭재 처리에 대한 잡초 억제 효과를 조사하였다. 대표적 잡초인 쑥군락과 바랭이군락을 대상으로 고정방형구 (1×1㎡)를 3반복 설치하였다. 처리구의 유기물 멀칭재는 5가지 재료로 활엽수 우드칩, 침엽수 바크, 갈참나무 낙엽, 메타세쿼이 아 낙엽, 칠엽수 과피를 사용하였다. 멀칭재 중에서 갈참나무 낙엽, 활엽수 우드칩, 칠엽수 과피가 비교적 잡초 억제 효과가 높은 것으로 나타났다. 갈참나무 낙엽은 지중 온도를 낮게 유지 하는 효과가 상대적으로 좋았기 때문에 토양의 보습 효과가 뛰 어날 것으로 판단된다. 유기물 멀칭재 처리는 일년생식물의 발 생은 억제하고, 지중식물 및 반지중식물의 생육에 도움을 주는 효과가 있었다. 멀칭재의 무게보다 재료에 의한 빛 차단 면적이 잡초를 억제하는 주된 요인이었다. 본 연구 결과는 국립수목원 전시원에서 발생하는 부산물을 활용한 친환경적 관리 방안 수립 에 활용될 것이며, 향후 잡초의 발생 시기에 따른 멀칭 시기 및 유기물 멀칭재의 유지 관리에 대한 추가적인 연구가 필요하다.
Coffee is a major traded item worldwide. Uganda, where the coffee sector provides a livelihood to 1.8 million households, is Africa’s second-biggest coffee exporter. Pests and diseases are significant constraints affecting coffee production. Although the Ugandan government has implemented strategies to assist farmers in addressing these constraints, coffee pests and diseases continue to affect the yield and quality of coffee crops. This ongoing issue highlights the need for more effective and sustainable solutions to protect coffee production in Uganda. This review examined two prevalent diseases and two major pests known to significantly impact Uganda’s coffee systems. It explored strategies that pathogens and pests would utilize to invade and colonize coffee plants. Furthermore, this review evaluated current challenges and prospects for improving coffee pest and disease management. By offering valuable insights and recommendations, it aims to equip agricultural stakeholders with the knowledge needed to develop and implement more effective strategies for combating these persistent threats to coffee production in Uganda.
This study was conducted to investigate changes in immunoglobulin G (IgG) concentration, nutrient content, and microbial communities of fresh and heat-treated Holstein colostrum collected from a colostrum bank operated by a local agricultural technology center in Gyeongsangbuk-do, South Korea. Of the 16 colostrum samples, 8 were heated at 60℃ for 30 min under a pressure of 0.9–1 bar. The colostrum samples were stored at −70℃ until use, at which time they were thawed at 50–55℃ in a water bath to analyze IgG levels, chemical composition, and microbiome, which was identified by 16S rRNA gene sequencing using the Illumina MiSeq-PE250 platform. The IgG concentrations were similar in fresh and heat-treated colostrum. The fat, protein, and lactose contents also did not differ in these samples. However, somatic cell count (SCC) was lower in heat-treated colostrum than those in fresh colostrum (p<0.05). At the phylum level for the microbiome of fresh colostrum, Proteobacteria (44.16%) was the most abundant taxa, followed by Bacteroidota (33.26%), Firmicutes (10.04%), Actinobacteriota (7.14%), and a marginal difference in the order of abundance was observed in heat-treated colostrum. At the genus level, bacteria belonging to Sphingomonas, Delftia, Ochrobactrum, Simplicispira, and Lactobacillus were more abundant (p<0.05) in the heat-treated colostrum, while the abundance of Acinetobacter in the fresh colostrum was four times more (p<0.05) than that in the heat-treated colostrum. Our results demonstrated that heating does not affect IgG level and colostrum composition but reduces SCC (p<0.05), suggesting that heat-treated colostrum can potentially be put to further use (e.g., feeding Hanwoo calves) without compromising its quality. Differences in the microbiome between the fresh and heat-treated colostrum were limited. Further studies are required to extensively investigate the quality and safety of colostrum collected from dairy farms to ensure better utilization and processing at a local agricultural technology center.
Probiotics have been evaluated as therapeutic agents for cancer treatment in an increasing number of studies. This study investigated the inhibitory and cytotoxic effects of specific Lactobacillus strains on a human colorectal adenocarcinoma cell line (HT-29). The strains assessed were Limosilactobacillus (L.) reuteri VA 102, Ligilactobacillus (L.) animalis VA 105, and Limosilactobacillus (L.) reuteri KCTC 3594 (ATCC 23272). The viability of HT-29 cells was evaluated using the MTT assay. The findings revealed that cell-free supernatants (CFS) exhibited significant anticancer effects. Heat-inactivated L. reuteri VA 105 and L. reuteri KCTC 3594 induced a pronounced reduction in cell viability. Furthermore, live cultures of L. reuteri VA 105 and L. reuteri VA 102 also showed reduced cell viability compared to the control group. These results suggest that CFS and heat-inactivated cells may be more suitable for therapeutic applications than live bacteria owing to their improved safety profiles and reduced potential for adverse effects. Our findings also emphasize the potential anticancer benefits of these LAB strains.
Because intact FMDV particles (146S) are often unstable in vitro, stabilizing foot-and-mouth disease virus (FMDV) antigens remains a key challenge in studying viral charateristics. Therefore, finding optimal condition to stabilize the FMDV is essential. In this study, we investigated formulations and potentials of several stabilizers such as appropriate buffer, excipients, and storage conditions to enhance the stability of 146S. Inactivated FMDV O-Jincheon (O-JC) was dissolved in various buffer formulations, and stored at 4℃ for two months to evaluate quantity of 146S at every 2-week interval. Among phosphate buffered saline (PBS), Tris buffered saline (TBS), HEPES buffered saline (HBS), and MOPS buffered saline (MBS), PBS showed more effective 146S stabilization that showed 1.3-1.6 fold higher 146S fraction than TBS, HBS, and MBS after storage for 2 weeks. However, constant dissociations of 146S were observed in all formulations at 8 weeks. Compared with other FMDVs, A22 Iraq and SAT-1, in PBS, O-JC proved to be the least stable in PBS. A variety of excipients including carbohydrate, sugar alcohol, cryo-protectant were tested for the capability in protecting O-JC from dissociation. By adding 4-8% sucrose, more than 60% of 146S fractions were maintained at 8 weeks, those were at least 1.8 fold higher than the PBS-only control. Addition of 1% β-cyclodextrin showed synergistic enhancement in O-JC stability. As the results of this study, it could be suggested that the PBS-based buffer together with 4-8% sucrose + 2% sorbitol or 2% sucrose + 2% sorbitol + 1% β-cyclodextrin could help the better stability of the O-JC in vaccine preparation.
Rapidly changing environmental factors due to climate change are increasing the uncertainty of crop growth, and the importance of crop yield prediction for food security is becoming increasingly evident in Republic of Korea. Traditionally, crop yield prediction models have been developed by using statistical techniques such as regression models and correlation analysis. However, as machine learning technique develops, it is able to predict the crop yield more accurate than the statistical techniques. This study aims at proposing the onion yield prediction framework to accurately predict the onion yield by using various environmental factor data. Temperature, humidity, precipitation, solar radiation, and wind speed are considered as climate factors and irrigation water and nitrogen application rate are considered as soil factors. To improve the performance of the prediction model, ensemble learning technique is applied to the proposed framework. The coefficient of determination of the proposed stacked ensemble framework is 0.96, which is a 24.68% improvement over the coefficient of determination of 0.77 of the existing single machine learning model. This framework can be applied to the particular farmland so that each farm can get their customized prediction model, which is visualized by the web system.