거저리는 식품으로 사용되기 때문에 유충기가 오래 지속되면 더 좋다. 반면에 거저리의 개체수 유지를 위 해 성장을 가속화하기 위해서는 유충이 빨리 성충이 되면 더 좋다. 이 연구에서는 개체군 밀도가 거저리의 발달 시 간에 미치는 영향을 구명하였다. 이를 위해 상단 7 cm, 하단 5 cm, 높이 3 cm 크기의 용기를 사용했다. 거저리는 용기 당 1, 2, 5, 10, 20마리의 밀도로 용기에서 서식하였다. 용기에 밀기울 1 g을 넣고 거저리의 먹이 여부에 따라 라벨을 붙였다. 실험은 세 번 반복되었다. 모든 실험에서 개체군 밀도가 높을수록 유충에서 번데기로의 변환 시간이 짧았 지만 번데기에서 성충으로 변환되는 시간은 크게 다르지 않았다. 또한 먹이가 있는 그룹에서 번데기로의 변환 시간 이 단축되었지만, 성충으로 변환되는 시간에는 차이가 없었다. 이 연구 결과는 유충기를 연장하기 위해 더 낮은 밀 도가 필요하고 더 빠른 속도로 성충이 필요하다면 밀도가 더 높아야 한다는 것을 보여주었다. 결론적으로 거저리의 발달 시간은 개체수 밀도에 의해 제어할 수 있을 것이다.
High-entropy alloys (HEAs) have been reported to have better properties than conventional materials; however, they are more expensive due to the high cost of their main components. Therefore, research is needed to reduce manufacturing costs. In this study, CoCrFeMnNi HEAs were prepared using metal injection molding (MIM), which is a powder metallurgy process that involves less material waste than machining process. Although the MIM-processed samples were in the face-centered cubic (FCC) phase, porosity remained after sintering at 1200°C, 1250°C, and 1275°C. In this study, the hot isostatic pressing (HIP) process, which considers both temperature (1150°C) and pressure (150 MPa), was adopted to improve the quality of the MIM samples. Although the hardness of the HIP-treated samples decreased slightly and the Mn composition was significantly reduced, the process effectively eliminated many pores that remained after the 1275°C MIM process. The HIP process can improve the quality of the alloy.
Despite advancements in therapeutic approaches, radiotherapy and cisplatin-based chemotherapy remain primary noninvasive treatments for patients with oral squamous cell carcinoma (OSCC). Moreover, the 5-year survival rate for patients with OSCC has remained almost unchanged for several decades, and many side effects of chemotherapy still exist. In this study, three-dimensional (3D) models of OSCC were established using fibroblasts, and the efficacy of various biological inhibitors was evaluated. A culture of epithelial cells with two types of fibroblasts (hTERT-hNOFs and cancer-associated fibroblasts) within a type I collagen matrix resulted in the formation of a continuous layer of tightly packed cells compared to models without fibroblasts. Furthermore, the effects of biological chemicals, including Y27632, latrunculin A, and verteporfin, on these models were investigated. The stratified formation of the epithelial layer and invasion in OSCC 3D-culture models were effectively inhibited by verteporfin, whereas invasion was weakly inhibited by Y27632 and latrunculin. Collectively, the developed OSCC 3D-culture models established with fibroblasts demonstrated the potential for drug screening, with verteporfin showing promising efficacy.
주변 국가인 태국, 캄보디아, 베트남, 라오스 등에서 벼멸구(Nilaparvata lugens)와 흰등멸구(Sogatella furcifera)를 채집하던 중, 벼멸구와 형태가 아주 유사한 이삭멸구(N. muiri)와 벼멸구붙이(N. bakeri), 그리고 흰등 멸구와 형태가 아주 유사한 흰등멸구붙이(S. kolophon), 피멸구(S. vibix) 그리고 애멸구(Laodelphax striatellus)가 동시에 채집이 되는 등 형태적 차이점이 거의 없어 전문가도 쉽게 구분하지 못하는 문제가 있음이 확인되었다. 따라서 형태가 유사한 상기 멸구류의 종 동정을 확실히 할 수 있는 PCR용 프라이머의 개발을 위해 벼멸구 및 흰등멸구의 미토콘드리아 내 COI 영역을 특이적으로 검출할 수 있는 프라이머 세트를 제작하고 종 동정 효과를 확인하였다.
The growth characteristics according to temperature conditions were investigated in the breeding room of the Sericulture & Entomology Experiment Station for Oriental garden crickets(Teleogryllus emma Ohmachi et Matsuura) and Modeagali-crickests(Loxoblemmus doenitzi Stein) collected from the lawns of Byeonsan-myeon, Buan-gun, Jeollabuk-do. The temperature conditions were 6 treatments from 15°C to 40°C at 5°C intervals using a multi-incubator, and the development period and mortality rate by age were compared using the 28°C breeding room conditions as a control. For T. emma, the higher the temperature, the shorter the total development period was, and the same trend was observed for the growth period by age stage. However, at low temperatures of 15°C and 20°C, all died after the third instar, and at high temperatures above 35°C, all died during development. At 25°C and 30°C, they developed normally, and the mortality rate was about 25%. The L. doenizi had the same tendency as the T. emma, with the higher the temperature, the shorter the development period. The total development period was 57.7 days at 25°C, which was similar to the T. emma's 55.9 days, and the mortality rate was the lowest at 44% at 25°C.
In 2022, research for native prokaryotic species in Korea reported 10 unrecorded bacterial strains affiliated to phyla Actinomycetota, Bacillota, and Pseudomonadota. The strains formed monophyletic clades with the most closely related species (with ≥98.7% sequence similarity) in the 16S rRNA gene sequencing. Among them, four species of the phylum Actinomycetota, two species of the phylum Bacillota, and four species of the phylum Pseudomonadota have not been reported in Korea, suggesting unrecorded species in Korea. Information on strains such as Gram staining reaction, colony and cell morphology, biochemical characteristics, and isolation sources were provided in the species description.
High-entropy alloys (HEAs) are attracting attention because of their excellent properties and functions; however, they are relatively expensive compared with commercial alloys. Therefore, various efforts have been made to reduce the cost of raw materials. In this study, MIM is attempted using coarse equiatomic CoCrFeMnNi HEA powders. The mixing ratio (powder:binder) for HEA feedstock preparation is explored using torque rheometer. The block-shaped green parts are fabricated through a metal injection molding process using feedstock. The thermal debinding conditions are explored by thermogravimetric analysis, and solvent and thermal debinding are performed. It is densified under various sintering conditions considering the melting point of the HEA. The final product, which contains a small amount of non-FCC phase, is manufactured at a sintering temperature of 1250oC.