In this study, we analyzed the structural and mechanical properties of aluminum foams fabricated using aluminum powders of varying sizes and mixtures. The effects of sintering and pore structure at each size on the integrity and mechanical properties of the foams were investigated. Structural characteristics were examined using scanning electron microscopy and micro–computed tomography, while mechanical properties were evaluated through compression testing. The experimental results demonstrated that smaller powder sizes improved foam integrity, reduced porosity and pore size, and resulted in thinner cell walls. In combination, these effects increased compressive strength as the powder size decreased. The findings of this study contribute to the understanding and improvement of the mechanical properties of aluminum foams and highlight their potential for use in a wide range of applications.
Italian ryegrass (Lolium multiflorum Lam., IRG) is a widely cultivated winter forage crop known for its high yield and nutritional value. This study evaluated the processing characteristics and feeding performance of IRG-based pellets in Hanwoo cattle (Bos taurus coreanae) and Korean native black goats (Capra hircus). IRG was harvested at the optimal growth stage and processed into two pellet formulations: IRG ≥80% (with up to 20% soybean meal) and 100% IRG. Feeding trials were conducted under ad libitum feeding conditions. Hanwoo cattle showed higher intake of 100% IRG pellets (7.9 kg/day/head) than IRG ≥80% pellets (7.5 kg/day/head, p<0.05), with similar average daily gain (0.9 ± 0.4 kg/day/head). Conversely, black goats exhibited significantly lower intake of IRG ≥80% pellets (54.6 g/day/head) compared to 100% IRG pellets (266 g/day/head), likely due to reduced palatability associated with soybean meal inclusion. These findings suggest that IRG pellets are suitable for Hanwoo cattle, while further optimization of pellet size and formulation is required to improve acceptance in goats. Future studies should assess long-term impacts on digestion, rumen fermentation, and metabolic responses.
This study was conducted to reset the withdrawal time (WT) for amoxicillin (AMX) in pigs as a part of positive list system (PLS) program introduction. Forty-two healthy pigs were orally administered with AMX at doses of 10 mg/kg body weight (BW) (AMX-1, n=20) and 20 mg/kg BW (AMX-2, n=20), twice daily for 5 days, respectively. After the treatment, tissue samples were collected from four pigs at 1, 3, 5, 7 and 14 days post-administration, respectively. Based on a previously established analysis method, residual AMX concentrations in pig tissues were determined using LC-MS/MS. In both AMX-1 and AMX-2 groups, AMX levels in all tissues except fat was below the limit of quantification (LOQ) at one day after the final administration. According to the European Medicines Agency’s guideline on determination of withdrawal periods, the withdrawal periods for AMX-1 and AMX-2 in fat tissue were established as 0 and 2 days, respectively. In conclusion, the estimated WT of AMX in edible tissues of pigs is shorter than the current WT recommendation of 5 days for AMX.
This study evaluated the bactericidal efficacy of a disinfectant containing chlorine dioxide as its main ingredient against Paenibacillus larvae (P. larvae) that is the causative agent of American foulbrood. A bactericidal efficacy test by broth dilution method was used to determine the lowest effective dilution of the disinfectant following exposure to P. larvae for 30 min at 4°C. The disinfectant and test bacterium were diluted with low and high organic matter (OM) suspension according to treatment condition. On low and high OM conditions, the bactericidal activity of the disinfectant against P. larvae was 2.5 and 1.25 fold dilution, respectively. The recommended dilution time of the disinfectant in low and high OM was 2.0 and 1.0 fold dilution, respectively. As the disinfectant possesses bactericidal efficacy against P. larvae, the disinfectant can be used to prevent American foulbrood in larvae of honeybees.
This study investigated the flowering response of three Korean native Aster species, namely A. hayatae, A. spathulifolius, and A. koraiensis, to varying photoperiods. Three-month-old plants propagated from cuttings were grown under four different photoperiods: 9, 12, 14, and 16 h. Aster hayatae flowered under all conditions, with flowering rates of 92%, 85%, 65%, and 27% under 9-, 12-, 14-, and 16-h photoperiods, respectively. Flowering in A. hayatae was promoted by shorter photoperiods, classifying it as a facultative short-day plant. Aster spathulifolius flowered only under 9- and 12-h photoperiods, with no significant difference between these treatments, suggesting that the species is an obligate short-day plant. However, given the low A. spathulifolius flowering rates of 27% and 13% under 9- and 12-h photoperiods, respectively, further research is required. Aster koraiensis did not flower under any photoperiod, possibly due to vernalization requirements or juvenility. These findings offer valuable insights into the photoperiodic flowering responses of these three Korean native Aster species, enhancing our understanding of their ecological traits and potential horticultural applications.
본 논문은 라이소자임이 칸디다 알비칸스에 항균효능이 있음을 발견하였고 라이소자임의 분해 절편도 또한 항균효능이 있는지 단백질 분해 효소인 트립신을 처리하여 확인해 보았다. 130개의 아미노산 으로 구성된 14 kDa 단백질인 라이소자임을 약 24 kDa의 분자량을 가지는 단백질 분해 효소인 트립신으 로 분해 하였다. 분해된 생성물은 고성능 액체 크로마토그래피인 분석용 및 제조용 HPLC를 사용하여 분 석 및 분리하였다. 이를 통해 효율적인 라이소자임 소화를 위한 최적 조건을 확인하고, 분해된 펩타이드 절 편들을 분리하였다. 효능평가 결과, 일부 펩타이드 절편들이 칸디다 알비칸스에 강한 항균 활성을 보임을 확인하였으며 몇몇은 활성이 줄어드는 결과를 보였다.
Supercapacitors, renowned for their high power density and rapid charge-discharge rates, are limited by their low energy density. This limitation has prompted the need for advanced electrode materials. The present study investigated reduced graphene oxide (rGO) in two distinct structures, as a film and as an aerogel, for use as supercapacitor electrodes. The rGO film, prepared by vacuum filtration and thermal reduction, exhibited a compact, lamellar structure, while the aerogel, synthesized through hydrothermal treatment, was a highly porous three-dimensional network. Electrochemical analyses demonstrated the aerogel’s superior performance, as shown by a specific capacitance of 121.2 F/g at 5 mV/s, with 94% capacitance retention after 10,000 cycles. These findings emphasize the importance of structural design in optimizing ion accessibility and charge transfer. They also demonstrate the potential of rGO aerogels for increasing the energy storage efficiency of advanced supercapacitor systems.
온실 내부 환경은 지역에 따라 외부 환경의 영향을 지속적으로 받는다. 본 연구는 몽골, UAE(아부다비), 호 주(퀸슬란드) 등 지역별로 구축된 한국형 스마트 온실의 환경 특성을 비교하고자 수행하였다. 몽골과 아부다비의 온실 모두 내외부 엔탈피 차이가 감소함에 따라 환기율이 증가하였다. 아부다비의 반밀폐형 온실에서는 10시부터 14시까지 평균 내부 기온이 외부 기온보다 약 7-10°C 낮았고 내부 VPD(12mbar)는 외부 VPD(56mbar)보다 4.6 배 낮았는데 이 결과는 포그 시스템 운영과 관련이 있는 것으로 보인다. 퀸즐랜드 온실의 경우, 내부 온도가 외부 온 도보다 11시 기준 약 3.81°C 높았고, 내부 엔탈피와 VPD가 외부 온도보다 높았으며, 내부와 외부의 엔탈피 차이가 증가함에 따라 환기율이 증가하였다. 이 결과로 엔탈피를 낮추는 것은 환기와, VPD를 낮추는 것은 포그 시스템 작 동과 관련이 있는 것을 알 수 있다. 또한, 작물 생육에 적합한 환경 조건을 효과적으로 관리하기 위해 엔탈피와 VPD 기반의 포그, 환기 또는 난방 시스템이 필요하다는 것을 알 수 있다.
Pluripotent stem cells (PSCs) are undifferentiated cells with the potential to develop into all cell types in the body. They have the potential to replenish cells in tissues and organs, and have unique properties that make them a powerful tool for regenerative therapy. Embryonic stem cells (ESCs) derived from the inner cell mass of the blastocyst of pre-implantation embryo and epiblast stem cells (EpiSCs) derived from the epiblast layer of post-implantation embryo are the well-known PSCs. These stem cells can differentiate into any of three germ layers of germ cells (endoderm, mesoderm and ectoderm). Additionally, induced pluripotent stem cells (iPSCs) refer to adult somatic cells reprogrammed to return to the pluripotent state by introducing specific factors. This is a breakthrough in stem cell research because ethical concerns such as fertilized embryo destruction can be avoided. PSCs have tremendous potential in treating degenerative cells by generating the cells needed to replace damaged cells, which can also allow to generate specific cell types to study the mechanisms of the disease and create disease models that screen for potential drugs. However, if the proliferative capacity of PSCs is not controlled, there is a risk that tumors will form, as this can lead to uncontrolled growth in their proliferative capacity. In addition, when PSCs are used for therapeutic purposes, there is a risk that the body’s immune system rejects the transplanted cells when the transplanted cells do not originate from the patient’s own tissue. Taken together, PSC is the foundation of stem cell research and regenerative medicine, providing disease treatment and animal development understanding. We would like to explain the classification of PSCs based on their developmental potential, the types of PSCs (ESCs, EpiSCs and iPSCs), their pluripotent status (naïve vs. primed) and alkaline phosphatase (AP) in PSCs and PSCs in domestic animals.