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.
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.
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.
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.
Background: Pluripotent stem cells (PSCs) are capable of differencing into various cell types in the body, providing them valuable for therapy of degenerative diseases. Patientspecific treatments using PSCs, such as mesenchymal stem cells in patient’s own body, may reduce the risk of immune rejection. Inducing the differentiation of PSCs into vascular endothelial cells (ECs) altering culture conditions or using specific growth factors is able to applied to the treatment of vascular diseases. The purpose of this study was to induce the differentiation of porcine epiblast stem cells (pEpiSCs), bone marrow-derived mesenchymal stem cells (pBM-MSCs) and adipose-derived mesenchymal stem cells (pAMSCs) into ECs and then examine the functionality of vascular ECs. Methods: Porcine pEpiSCs, pBM-MSCs and pA-MSCs were induced to differentiate into ECs on matrigel-coated plates in differentiation medium (EBM-2 + 50 ng/mL of VEGF) for 8 days. Cells differentiated from these stem cells were isolated using CD-31 positive (+) magnetic-activated cell sorting (MACS) and then proliferated in M199 medium. Evaluation of ECs differentiated from these stem cells was treated with capillary-like structure formation and three-dimensional spheroid sprouting assay. Results: Porcine pEpiSCs, pBM-MSCs and pA-MSCs showed similar expression of pluripotency-related genes (OCT-3/4. NANOG, SOX2). These stem cells were differentiated into vascular ECs, but showed different morphologies after the differentiation. Cells differentiated from pEpiSCs showed an elongated spindle-like morphology, whereas cells differentiated from pBM-MSCs showed a round pebble-like morphology. In the case of pA-MSCs, these two morphologies were mixed with each other. Additionally, vascular ECs differentiated from these stem cells showed different formation of capillary-like structure formation and three-dimensional spheroid sprouting assay. Conclusions: Cells differentiated from pEpiSCs, pBM-MSCs and pA-MSCs presented the functionality of different vascular ECs, demonstrating the potential of the excellent ECs differentiated from pEpiSCs.
This study aimed to examine the relationship between foreign direct investment and economic growth of ASEAN countries. This study also discovered impacts of other factors such as labor force, trade openness, gross fixed capital formation, domestic credit, and pandemic on economic growth. We used country panel data during the period of 1998-2021 from nine ASEAN countries including Brunei Darussalam, Cambodia, Indonesia, Lao PDR, Malaysia, Myanmar, Philippines, Thailand, and Vietnam. Data were collected from world development indicators of the World Bank and UNCTAD database. Estimation results from fixed effects models showed a consistency in terms of impact of foreign direct investment on economic growth between two outputs (GDP per capita and national GDP). This study found that foreign direct investment had a positive and significant effect on economic growth in the ASEAN region. Moreover, control factors also impacted economic growth positively, except for COVID- 19 v ariable, w hich h ad a n egative impact. Labor force had the strongest impact, followed by gross fixed capital formation, COVID-19, and bank credit. Based on these results, some implications for ASEAN policymakers are suggested.
목적 : 누진 가입도 안경 착용자의 안경테의 크기와 얼굴 형태에 적합한 안경테를 비교하여 안경테 크기와 신체 적(역학적) 불편감 사이의 연관성을 조사하였다. 방법 : 누진 가입도 안경 착용자 중 안경의 피팅 상태가 적절한 71명(남성 37명, 여성 34명, 평균 54.52±8.78 세)이 참여하였고, 신체적 불편감을 설문지로 조사하였다. 안경테 크기를 FHD(front horizontal dimension), FTB(front to bend), LOD(length of drop) 및 TL(temple length)로 확인하였다. 얼굴 형태를 계측한 후 얼굴에 적합한 안경테 크기를 계산하였고, 착용하고 있는 안경테 크기와 비교하였다. 결과 : 신체적 불편감의 정도는 관자놀이 눌림, 흘러내림, 코 눌림, 귀 눌림 순으로 높았으며, 불편함을 경험한 비율은 흘러내림, 코 눌림, 귀 눌림, 관자놀이 눌림 순으로 높았다. 착용한 안경테의 FHD는 남녀 모두 얼굴 계측 으로 계산한 안경테 설계값보다 작았다(p=0.001). 착용한 안경테의 FTB는 남녀 모두 안경테 설계값보다 작았으 며, 착용한 안경의 LOD는 설계값보다 컸고 여성은 남성보다 길었다(all, p=0.001). 결론 : 착용한 남녀 안경의 FHD는 얼굴 형태에 비해 작아 관자놀이 눌림의 원인이 될 수 있고, 측면부 LOD는 얼굴에 비해 커서 흘러내림과 코 눌림의 원인이 될 수 있다. 얼굴 형태에 적합한 안경테 크기를 선택할 수 있도록 안경테의 FHD와 측면부 전체 길이(FTB+LOD)가 여러 사이즈로 제작되어야 할 것이다.