In this study, we examined the antagonistic effects of sprout-borne lactic acid bacteria (LAB) on Salmonella enterica serovar Enteritidis. This antagonism is promoted as a means of controlling contamination during sprout production and provides additional LAB for consumers. We isolated a total of 24 LAB isolates in nine species and five genera from seven popular vegetable sprouts: alfalfa (Medicago sativa), clover (Trifolium pratense), broccoli (Brassica oleracea ssp. italica), vitamin (B. rapa ssp. narinosa), red radish (Raphanus sativus), red kohlrabi (B. oleracea var. gongylodes), and Kimchi cabbage (B. campestris var. pekinensis). Based on 16S rRNA gene sequences, the LAB species were identified as Enterococcus casseliflavus, E. faecium, E. gallinarum, E. mundtii, Lactococcus taiwanensis, Leuconostoc mesenteroides, Pediococcus pentosaceus, and Weissella cibaria, and W. confusa. A total of 16 LAB isolates in seven species including E. faecium, E. gallinarum, E. mundtii, L. taiwanensis, L. mesenteroides, P. pentosaceus, and W. cibaria showed antagonistic activity toward S. enterica. The growth inhibition of sprout LAB on S. enterica was confirmed by co-culture. Unexpectedly, sprout LAB failed to suppress the growth of S. enterica in alfalfa sprouts, whereas all LAB strains stimulate S. enterica growth even if it is not significant in some strains. The findings of this study indicate that S. enterica-antagonistic LAB are detrimental to food hygiene and will contribute to further LAB research and improved vegetable sprout production.
Domestic commercial low- and intermediate-level radioactive waste storage containers are manufactured using 1.2 mm thick cold-rolled steel sheets, and the outer surface is coated with a thin layer of primer of 10~36 μm. However, the outer surface of the primer of the container may be damaged due to physical friction, such as acceleration, resonance, and vibration during transportation. As a result, exposed steel surfaces undergo accelerated corrosion, reducing the overall durability of the container. The integrity of storage containers is directly related to the safety of workers. Therefore, the development of storage containers with enhanced durability is necessary. This paper provides an analysis of mechanical properties related to the durability of WC (tungsten carbide)-based coating materials for developing low- and intermediate-level radioactive waste storage containers. Three different WC-based coating specimens with varied composition ratios were prepared using HVOF (high-velocity oxy-fuel) technique. These different specimens (namely WC-85, WC-73, and WC-66) were uniformly deposited on cold-rolled steel surfaces ensuring a constant thickness of 250 μm. In this work, the mechanical properties of the three different WCbased coaitng materials evaluated from the viewpoints of microstructure, hardness, adheision force between substrate and coating material, and wear resistance. The cross-sectional SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-ray Spectroscopy) images revealed that elements W (tungsten), C (carbon), Ni (nickel), and Cr (chromium) were uniformly distributed within the each coating layers which was approximately 250 μm thick. The average hardness values of HWC-85 and HWC-73 were found to be 1,091 Hv (Vickers Hardness) and 1,083 Hv, respectively, while the HWC-66 exhibited relatively lower hardness value of 883 Hv. This indicates that a higher WC content results in increased hardness. Adhesion force between and substrates and coating materials exceeded 60 MPa for all specimens, however, there were no significant differences observed based on the tungsten carbide content. Furthermore, a taber-type abrasion tester was used for conducting abrasion resistance tests under specific conditions including an H-18 load weight at 1,000 g with rotational speed set at 60 RPM. The abrasion resistance tests were performed under ambient temperatures (RT: 23±2°C) as well as relative humidity levels (RH: 50±10%). Currently, the ongoing abrasion resistance tests will include some results in this study.
As the demand for nuclear power increases as a means to achieve carbon neutrality, concerns about nuclear proliferation have also grown. Consequently, significant researches have conducted to enhance nuclear non-proliferation resistance. Among these research, nuclear material attractiveness is a methodology used to evaluate how appealing a particular material is for potential use in nuclear weapons, based on the characteristics of that material. Existing nuclear material attractiveness assessments focused on materials like U, Pu, and TRU, which could be directly used in the production of nuclear weapons. However, these assessments did not consider how the properties of nuclear materials change throughout the nuclear fuel cycle, with each facility process. This study assumed a scenario of the nuclear fuel cycle of graphite reduction reactors and analyzed including enrichment facilities and PUREX. This study used the FOM (Figure-Of-Merit) method developed by LANL (Los Alamos National Laboratory) for evaluating the nuclear material attractiveness. The FOM formula consists of three parameters such as critical mass, heat content, and dose The critical mass of targe materials and the dose evaluation were conducted using the Monte Carlo N-Particle code. The heat content was calculated using the ORIGEN code embedded in the Scale code. In particular, if U-238 is dominant in the facility’s materials, such as mining and refining facilities, and critical mass evaluation is unpractical. Therefore, 1SQ (Significant Quantity) of that uranium was assumed as the critical mass value for the FOM evaluation, even though 1SQ is not identical to the critical mass As a result of this study, the attractiveness of Pu produced by PUREX among all nuclear fuel cycle facilities was 2.7616, which was the most attractive to be diverted to nuclear weapons. Through this study, it was shown that the proliferation risk of the nuclear facilities in the nuclear fuel cycle and risk of diversion among those facilities.
본 연구는 국내의 한우 개량에 있어서 정확한 혈통 정보가 중요해짐에 따라 고밀도 Single Nucleotide Polymorphism (SNP) chip의 SNP 정보들을 활용한 친자 확인으로 혈통 정보의 신뢰도 향상에 기여하고자 실시하였다. 이미 혈통 정보가 확인되고 Microsatellite (MS) 유전자형으로 친자 여부가 확인된 14개의 가계, 318두로 친자 확인 분석을 하였다. Call rate 100%인 마커들을 활용한 친자 확인 분석 결과, 9두가 모 부정, 19두가 완전 부정으로 총 28두가 부정으로 판정되었고, 이는 부모의 SNP 정보에서 나올 수 있는 조합과 다른 자식의 유전자형이 확인되었다. 이후, 친자 확인 정확도 향상을 위해 call rate와 minor allele frequency (MAF)를 기준으로 SNP 마커 수를 증가시켜 분석하였으나 부정으로 판정되는 개체들이 추가적으로 발생하였고, 이는 SNP 정보의 결측치 증가 및 자식의 유전자형 변이로 인한 것으로 판단된다. 따라서 고밀도 SNP chip을 활용한 친자 확인 분석에는 보다 신중한 접근이 필요하며, 본 연구 결과는 고밀도 SNP 정보를 이용한 친자 확인 연구에 있어서 기초자료로 활용될 수 있을 것으로 사료된다.
This study was aimed to isolate bacterial inoculants producing chitinase and evaluate their application effects on corn silage. Four corn silages were collected from four beef cattle farms to serve as the sources of bacterial inoculants. All isolates were tested against Fusarium graminearum head blight fungus MHGNU F132 to confirm their antifungal effects. The enzyme activities (carboxylesterase and chitinase) were also measured to isolate the bacterial inoculant. Based on the activities of anti-head blight fungus, carboxylesterase, and chitinase, L. buchneri L11-1 and L. paracasei L9-3 were subjected to silage production. Corn forage (cv. Gwangpyeongok) was ensiled into a 10 L mini silo (5 kg) in quadruplication for 90 days. A 2 × 2 factorial design consists of F. graminearum contamination at 1.0104 cfu/g (UCT (no contamination) vs. CT (contamination)) and inoculant application at 2.1 × 105 cfu/g (CON (no inoculant) vs. INO (inoculant)) used in this study. After 90 days of ensiling, the contents of CP, NDF, and ADF increased (p<0.05) by F. graminearum contamination, while IVDMD, acetate, and aerobic stability decreased (p<0.05). Meanwhile, aerobic stability decreased (p<0.05) by inoculant application. There were interaction effects (p<0.05) on IVNDFD, NH3-N, LAB, and yeast, which were highest in UCT-INO, UCT-CON, CT-INO, and CT-CON & INO, respectively. In conclusion, this study found that mold contamination could negatively impact silage quality, but isolated inoculants had limited effects on IVNDFD and yeast.
This study selected the optimal conditions for enzyme treatment that can promote the extraction of functional components from Salvia plebeia (SP) and confirmed solubilization characteristics, functional component contents, and applicability evaluation in pilot-scale, antioxidative, and anti-inflammatory activity. The optimal conditions of pectinase, 1%, and 2 h (P) were determined through the enzyme treatment of SP. The water-soluble index and total polyphenol content were the highest in P compared to 100oC reflux condition for 2 h (CON). Component analysis performed using liquid chromatography-mass spectrometry revealed that flavonoid contents were increased 6.6-9.5 times in the P compared to CON. There was no difference in component content when comparing the measurement lab-scale and pilot scale. CON and P indicated cytoprotective effect against H2O2-induced RAW 264.7 cells. CON and P pre-treatment also reduced the production of nitric oxide and proinflammatory cytokines in LPS-induced RAW 264.7 cells. Furthermore, P showed higher antioxidant and anti-inflammation activities than CON. These results suggested that P has a higher concentration of bioactive compounds through enzyme treatment than that obtained from CON. Thus, it can be used as a primary material for industrial utilization, such as developing functional food materials using SP.
Barnea manilensis is a bivalve which bores soft rocks, such as, limestone or mudstone in the low intertidal zone. They make burrows which have narrow entrances and wide interiors and live in these burrows for a lifetime. In this study, the morphology and the microstructure of the valve of rock-boring clam B. manilensis were observed using a stereoscopic microscope and FE-SEM, respectively. The chemical composition of specific part of the valve was assessed by energy dispersive X-ray spectroscopy (EDS) analysis. 3D modeling and structural dynamic analysis were used to simulate the boring behavior of B. manilensis. Microscopy results showed that the valve was asymmetric with plow-like spikes which were located on the anterior surface of the valve and were distributed in a specific direction. The anterior parts of the valve were thicker than the posterior parts. EDS results indicated that the valve mainly consisted of calcium carbonate, while metal elements, such as, Al, Si, Mn, Fe, and Mg were detected on the outer surface of the anterior spikes. It was assumed that the metal elements increased the strength of the valve, thus helping the B. manilensis to bore sediment. The simulation showed that spikes located on the anterior part of the valve received a load at all angles. It was suggested that the anterior part of the shell received the load while drilling rocks. The boring mechanism using the amorphous valve of B. manilensis is expected to be used as basic data to devise an efficient drilling mechanism.
The Republic of Korea is expected to participate in the denuclearization verification activities by the International Atomic Energy Agency (IAEA) in case any neighboring countries declared denuclearization. In this study, samples for the verification of nuclear activities in undeclared areas were selected for the denuclearization of neighboring countries, and the appropriateness of the procedures was considered. If a country with nuclear weapons declares denuclearization, it must be accompanied by the IAEA’s verification regarding nuclear materials and weapons in the declared and undeclared areas. The analysis of the process samples or on-site environmental samples and the verification of undeclared nuclear facilities and materials aid in uncovering any evidence of concealment of nuclear activity in undeclared areas. Therefore, a methodology was established for effective sampling and analysis in accordance with proper procedures. Preparations for sampling in undeclared areas were undertaken for various potential scenarios, such as, the establishment of zones according to radiation dose, methods of supplying electricity, wireless communication networks, targets of sampling according to characteristics of nuclides, manned sampling method, and unmanned sampling method. Through this, procedures were established for pre- and post-site settings in preparation for hazards and limiting factors at nuclear inspection sites.
본 연구에서는 생태모방적 관점에서 목질을 천공하는 송곳벌과 밑드리좀벌의 산란관의 형태적 특징을 비교하였다. 벌목에 속하는 송곳벌과 밑드리좀벌은 목질부를 천공하는 유사한 특징이 있으나 실체현미경, 전계방사형주 사전자현미경, 광학현미경을 이용하여 산란관의 형태적 특징을 관찰한 결과 두 종 간에 큰 차이를 보였다. 송곳벌의 산란관 말단은 등쪽과 배쪽에 모두 규칙적인 돌기가 발달하여, 회전형 드릴 비트와 흡사한 형태를 띤 반면 밑드리좀벌의 산란관 말단은 한쪽 방향에만 몇 개의 돌기가 있고 다른 부분은 매끄러워 마치 톱과 비슷한 형태를 보였다. 또한 얼룩송곳벌 산란관의 말단은 대칭적으로 4 등분으로 되어있다가 14번째 돌기를 지나면서 2 : 1 : 1의 비율로 3등분이 되는 반면, 밑드리좀벌 산란관의 말단은 2 : 1 : 1의 비율로 3등분되어 있음을 확인할 수 있었다. 또한, 송곳벌의 산란관의 중간을 수평으로 자른 단면구조에 서는 dovetail joint의 구조가 확인되었으며, 이를 통해 천공을 위해 수직 운동을 한다는 것을 확인할 수 있었다. 이러 한 두 종의 형태적 차이는 목질 부분을 먹이원으로 이용하는 송곳벌과 벌의 유충을 이용하는 밑드리좀벌의 생활방 식뿐만 아니라 계통분류학적 차이에 의해 기인한 것으로 사료된다. 끝으로, 산란관 말단 부분의 성분분석결과 두 종 모두에서 높은 강도의 특성을 부여하는 아연이 검출되었다. 이는 주로 목질을 천공하는 두 종의 생태적 적응 과정에 의하여 특이적으로 진화된 것으로 사료된다.
This experiment was conducted to assess the high antioxidant activity varieties of Chinese cabbage (Brassica rapa L. ssp. pekinensis) from the 55 accessions. The antioxidant activity of Chinese cabbage were determined by the TPC, TFC, DPPH, ABTS, and chlorophyll, carotenoid contents. The TPC and TFC showed a range of 1.21~4.61 mg GAE/g DW, 0.18~3.09 mg CE/g DW. The DPPH and ABTS assay were in the range of 0.65~4.36 and 1.42~6.91 mg ascorbic acid equivalent (ASCE)/g DW, respectively. The UPLC analysis was performed quantitatively to identify chlorophyll and carotenoid in the Chinese cabbage extract. The levels of the total chlorophyll and total carotenoid were 86.60~1,235.91, and 75.86~490.11 μg/g, respectively. The comprehensive differences in the total and individual chlorophyll contents have also been observed among different varieties. These results will be valuable as basic data for the standardization of Chinese cabbage.
The purpose of this study was to determine the content of polyphenols and flavonoids, vitamin C, and antioxidant activity for the extract from the Deodeok sprout. To accomplish this, the Deodeok sprout whole (CLS-W), above ground part (leaf, stem, CLS-L), and root (CLS-R) were individually extracted using 70% ethanol. The highest levels of total polyphenols and total flavonoids were observed in the Deodeok sprout extract CLS-L2. Similarly, antioxidant activities resulting in radical scavenging activities increased significantly in the extract of CLS-L2. In conclusion, these results indicate that Deodeok sprouts can be used as a viable, new natural antioxidant source.
The purpose of this study was to investigate the antioxidant activity and tyrosinase inhibitory activity of Codonopsis lanceolata 50% ethanol extract, and its solvent fractions (n-hexane, ethyl acetate (EA), n-butanol, water). The main components of the EA fraction were qualitatively analyzed using UPLC Q-ToF/MS. Additionally, a quantitative analysis was performed using UPLC. As a result, the total polyphenol content was 113.36 mg gallic acid/g in the EA fraction, which contained the largest amount of the C. lancolata solvent fractions. Also EA showed the highest antioxidant activity than other fractions. The IC50 of DPPH(2,2-diphenyl-1- picrylhydrazyl) radical scavenging activity was 0.03 mg/mL and the IC50 of ABTS [2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonate)] radical scavenging activity was 0.049 mg/mL. The EA fraction showed tyrosinase inhibitory activity than other fractions and especially inhibited monophenolase oxidase reaction higher than diphenolase oxidase reaction. The monophenolase oxidase inhibited 55% when the concentration of the EA fraction was 0.25 mg/mL. As a result of Q-ToF/MS analysis, it was confirmed that tangshenoside I and lobetyolin were the main components of EA fraction. Thus, these results suggest that C. lanceolata may be used as a potent source of cosmetic agents.