• Natural Product Sciences
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• 제20권4호
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• pp.301-305
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• 2014

The aim of our study is to investigate the anti-nociceptive and anti-inflammatory properties of an ethanol extract of the leaf and stem of Aralia cordata. Writhing responses induced by acetic acid, tail immersion test, and formalin-induced paw pain response for nociception and formalin-induced paw edema for inflammation were evaluated in mice. A. cordata (50 - 200 mg/kg, p.o.) and ibuprofen (100 mg/kg, p.o.), a positive non-steroidal anti-inflammatory drugs (NSAIDs), inhibited the acetic acid-induced writhing response, but they did not protect the thermal nociception in tail immersion test. However, morphine (5 mg/kg, s.c.) used as positive opioid control alleviated both the acetic acid-induced writhing response and thermal nociception in tail immersion test. In the formalin test, A. cordata (50 - 200mg/kg) and ibuprofen (200mg/kg) inhibited the second phase response (peripheral inflammatory response), but not the first phase response (central response), whereas morphine inhibited both phase pain responses. Both A. cordata (100 mg/kg) and ibuprofen (200 mg/kg) significantly alleviated the formalin-induced increase of paw thickness, the index of inflammation. These results show for the first time that the leaf and stem of A. cordata has a significant anti-nociceptive effect that seems to be peripheral, but not central. A. cordata also displays an anti-inflammatory activity in an acute inflammation model. The present study supports a possible use of the leaf and stem of A. cordata to treat pain and inflammation.

• Toxicological Research
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• 제29권4호
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• pp.221-227
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• 2013

Embryonic stem (ES) cells have potential for use in evaluation of developmental toxicity because they are generated in large numbers and differentiate into three germ layers following formation of embryoid bodies (EBs). In earlier study, embryonic stem cell test (EST) was established for assessment of the embryotoxic potential of compounds. Using EBs indicating the onset of differentiation of mouse ES cells, many toxicologists have refined the developmental toxicity of a variety of compounds. However, due to some limitation of the EST method resulting from species-specific differences between humans and mouse, it is an incomplete approach. In this regard, we examined the effects of several developmental toxic chemicals on formation of EBs using human ES cells. Although human ES cells are fastidious in culture and differentiation, we concluded that the relevancy of our experimental method is more accurate than that of EST using mouse ES cells. These types of studies could extend our understanding of how human ES cells could be used for monitoring developmental toxicity and its relevance in relation to its differentiation progress. In addition, this concept will be used as a model system for screening for developmental toxicity of various chemicals. This article might update new information about the usage of embryonic stem cells in the context of their possible ability in the toxicological fields.

• 공학교육연구
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• 제20권4호
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• pp.21-27
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• 2017

The purpose of this study is to provide basic data and guideline to STEM(Science, Technology, Engineering, Mathematics) educators who prepare engineering education in elementary and secondary school. For this, this study develops a composition model for engineering education program of elementary and secondary school. To do this, a literature research, experts interview and Delphi survey were conducted. Through the literature research, we extracted the components of model for engineering education program of elementary and secondary school and then made a first draft of the model. The draft was revised by experts while Delphi survey was used to validate the model based on Delphi panels' opinions. The panels for the Delphi survey consisted of 51 experts in the STEM education field. The survey was conducted three different times and importance survey was included in the third stage. The conclusions of this study were as follows: First, the model consist of definition, 4 directions, 4 characteristics, 3 educational goals according to school level, educational contents area and element, teaching and learning method and evaluation method. The educational contents area and element consist of 2 major areas, 7 areas and 18 elements. Second, all components of the developed model were valid in most of the statistics such as mean, standard deviation, the degree of consensus and convergence, and CVR(Content Validity Ratio). Third, importance for education contents area and element according to the school level are analyzed.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제28권6호
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• pp.520-530
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• 2006

Undifferentiated mesencymal stem cells(UMSCs) have been thought to be multipotent cells that can replicate as undifferentiated cells and that have the potential to differentiate into lineages of mesenchymal tissue including the bone, cartilage, fat, tendon, muscle, and marrow stroma. It can be used to sinus lifting, Guided bone regeneration, other bone graft in dental part. The purpose of this study is to evaluate the effect of mesencymal stem cells on sinus augmentation with autogenous bone, fibrin glue mixture in a rabbit model. 8 New Zealand white rabbits were divided randomly into 4 groups based on their time of sacrifice(1, 2, 4 and 8 weeks). First, undifferentiated mesenchymal stem cells were isolated from iliac crest marrow of rabbits and expanded in vitro. cell culture was performed in accordance with the technique described by Tsutsumi et al. In the present study, The animals were sacrificed at 1, 2, 4 and 8 weeks after transplantation, and the bone formation ability of each sides was evaluated clinically, radiologically, histologically and histomorphologically. According to the histological observations, Stem cell group showed integrated graft bone with host bone from sinus wall. At 2 and 4weeks, It showed active newly formed bone and neovascularization. At 8 weeks, lamella bone was observed in sinus graft material area. Radiologically, autobone with stem cell showed more radiopaque than autobone without stemcell. there were significant differences in bone volume between 2 and 4 weeks (p<0.05). In summary, the autobone with stem cells had well-formed, newly formed bone and neovasculization, compared with the autobone without stem cells (esp. 2 weeks and 4 weeks) The findings of this experimental study indicate that the use of a mixture of mesenchymal stem cell yielded good results in osteogenesis and bone volume comparable with that achieved by autogenous bone. Therefore, this application of this promising new sinus floor elevation method for implants with tissue engineering technology deserves further study.

• 한국작물학회지
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• 제51권6호
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• pp.539-543
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• 2006

Lodging is classified as root lodging caused by the loss of supporting force in the root, bending caused by the deformation of the stem and breaking where the stem breaks down as loads exceeding critical elasticity were applied. This research excluded breaking which is not in a state of equilibrium and tried to partition the level of lodging using an algebraic model in root lodging and stem lodging, or bending. When a vertical load was applied, the deformation of the stem of rice plant showed the form of a quadratic equation. The trace of the panicle neck in the process of lodging was an ellipse-shape. When loading was pure root lodging, the trace of the panicle neck became a circle of which culm length is the radius. When it was a pure stem lodging, the trace of the panicle neck is an ellipse of which major axis is culm length and minor axis is 0.64* culm length. When both stem lodging and root lodging occurred in a natural setting, the partitioning of lodging can be calculated by a formula using eccentricity of an ellipse, S=e*100/0.768(S is the ratio of stem lodging in the whole lodging, e is eccentricity of the ellipse). This method is expected to be useful in simple lodging partitioning. We could also calculate the partitioning of stem lodging and root lodging as units of angles as an accuracy method, by using a straight line calculated by differentiating a quadratic equation of stem deformation at the origin of the coordinates. These two methods for dividing root and stem lodging showed different values. However, each of them showed almost same values with different lodging degree in one plant.

• 한국산림과학회지
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• 제108권3호
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• pp.357-363
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• 2019

본 연구는 Kozak 수간곡선모델을 이용하여 우리나라 상수리나무의 입목수간재적표를 개발하고자 수행하였다. 전국의 분포하고 있는 상수리나무를 총 2,700본의 표준목을 벌채하여 수간고별 직경과 수간석해 자료를 수집하여 생장특성을 조사하였다. 수간곡선식의 적합도 검정을 위하여 적합도지수(Fitness index), 편차(Bias), 평균절대편차(Mean Absolute Deviation)를 이용하여 모델의 적합성을 판단하였다. 추정된 모델의 적합도지수는 97%로 나타났고 편차는 0.017, 평균절대편차는 1.118로 높은 적합도를 보였다. 또한 현행재적표와 신규재적표의 재적간의 차이를 분석한 결과, 통계적으로 유의적인 재적차이를 보였다(p = 0.0008, <0.005). 이는 현실림을 반영한 신규재적표를 이용하는 것이 목재자원량의 평가시 손실을 줄이고 국가 및 지자체의 산림통계의 정확도를 향상시킬 것으로 판단된다. 본 연구의 주요한 결과인 추정된 수간곡선식을 이용한 입목수간재적표는 우리나라의 주요 활엽수종인 참나무류 중 상수리나무의 생장 정보 및 합리적 경영을 위한 경영제표가 될 것으로 판단된다.

• 한국산림과학회지
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• 제96권1호
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• pp.40-47
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• 2007

본 연구는 전라북도 진안 지역의 낙엽송을 대상으로 지위지수 추정과 지위지수곡선 유도 및 간재적식 개발을 목적으로 하였다. 지위지수에 대한 식은 대수차분 방정식에 의해 개발되었다. 기초 연령 40년으로 한 다형 지위지수 패밀리 곡선은 Schumacher 수고 방정식을 기초로 표현하였다. 최적의 간재적 추정식은 $V=0.00260+0.00000399D^2H$로 판명되었다. 이 방정식에 사용한 동시 F-검정에서 추정된 간재적량은 모델 평가에 관한 실측된 간재적량과 유의(${\alpha}=0.05$)하게 다르지 않음을 보여주었다. 지위지수 곡선과 재적 추정식의 결과는 지위와 수확표 조제시 기초 자료로 제공할 수 있고, 진안지역 낙엽송 임분의 지역 산림경영에 사용될 수 있을 것이다.

• 대한본초학회지
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• 제38권6호
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• pp.29-44
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• 2023

Objectives : This study was planned to evaluate the therapeutic effectiveness and possible underlying mechanism of TPE (Tetrapanax papyrifer stem(inner part of the stem Extract) and AQE (Akebiae quinata stem Extract) on osteoarthritis. Methods : Osteoarthritis models were induced through intra-articular injection of MIA (monosodium iodoacetate) 50 μL with 80 mg/ml in rats. Excluding the normal group, Osteoarthritis-induced rats were divided into 4 groups (Control, INDO, TPE, AQE). The drug concentrations were indomethacin 5 mg/kg, TPE 200 mg/kg, and AQE 200 mg/kg, and were orally administered once a day for a couple of weeks. After drug supplementation, the effects of TPE and AQE were measured with serum diagnosis, western blotting, and histopathological staining. Results : It was found that the DPPH and ABTS free radical erasure ability of AQE was better than that of TPE. AQE administration improved rear limb overload and it led to relieving pain. Both PTE and AQE significantly reduced the expression of inflammatory mediators COX-2, iNOS, and inflammatory cytokine IL-1β and IL-6 by inhibiting the phosphorylation of IκBα and deactivating the pathway of NF-κBp65. On the other hand, TNF-α was significantly reduced only by administration of AQE. In addition, histopathological analysis showed that the administration of AQE compared to PTE suppressed cartilage degeneration and effectively suppressed damage to proteoglycan, a component of ECM. Conclusion : Reviewing these experimental results, TPE and AQE possessed the effect of delaying the progress of osteoarthritis and protecting cartilage. In addition, the results of this study show that AQE has a better cartilage protection effect than TPE.

• International Journal of Stem Cells
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• 제16권1호
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• pp.1-15
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• 2023

Liver organoids have gained much attention in recent years for their potential applications to liver disease modeling and pharmacologic drug screening. Liver organoids produced in vitro reflect some aspects of the in vivo physiological and pathological conditions of the liver. However, the generation of liver organoids with perfusable luminal vasculature remains a major challenge, hindering precise and effective modeling of liver diseases. Furthermore, vascularization is required for large organoids or assembloids to closely mimic the complexity of tissue architecture without cell death in the core region. A few studies have successfully generated liver organoids with endothelial cell networks, but most of these vascular networks produced luminal structures after being transplanted into tissues of host animals. Therefore, formation of luminal vasculature is an unmet need to overcome the limitation of liver organoids as an in vitro model investigating different acute and chronic liver diseases. Here, we provide an overview of the unique features of hepatic vasculature under pathophysiological conditions and summarize the biochemical and biophysical cues that drive vasculogenesis and angiogenesis in vitro. We also highlight recent progress in generating vascularized liver organoids in vitro and discuss potential strategies that may enable the generation of perfusable luminal vasculature in liver organoids.

• 한국독성학회:학술대회논문집
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• 한국독성학회 1998년도 국제심포지움 및 추계학술대회
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• pp.60-60
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• 1998