• Structural Engineering and Mechanics
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• 제83권4호
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• pp.495-513
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• 2022

This paper aims to study the fracture mechanism of rocks under the 'u'shape cutters considering the effects of crack (pre-existing crack) distances, crack spacing and crack inclination angles. The effects of loading rates on the rock fragmentation underneath these cutters have been also studied. For this purpose, nine experimental samples with dimensions of 5 cm×10 cm×10 cm consisting of the non-persistent cracks were prepared. The first three specimens' sets had one non-persistent crack (pre-existing crack) with a length of 2 cm and angularity of 0°, 45°, and 90°. The spacing between the crack and the "u" shape cutter was 2 cm. The second three specimens" set had one non-persistent crack with a length of 2 cm and angularity of 0°, 45°, and 90° but the spacing between pre-existing crack and the "u" shape cutter was 4 cm. The third three specimens'set has two non-persistent cracks with lengths of 2 cm and angularity of 0°, 45° and 90°. The spacing between the upper crack and the "u" shape cutter was 2 cm and the spacing between the lower crack and the upper crack was 2 cm. The samples were tested under a loading rate of 0.005 mm/s. concurrent with the experimental investigation. The numerical simulations were performed on the modeled samples with non-persistent cracks using PFC2D. These models were tested under three different loading rates of 0.005 mm/s, 0.01 mm/sec and 0.02 mm/sec. These results show that the crack number, crack spacing, crack angularity, and loading rate has important effects on the crack growth mechanism in the rocks underneath the "u" shape cutters. In addition, the failure modes and the fracture patterns in the experimental tests and numerical simulations are similar to one another showing the validity and accuracy of the current study.

• 대한한방부인과학회지
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• 제19권3호
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• pp.135-149
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• 2006

Purpose : This study was aimed to investigate the inhibitory effect of Millettia Reticulatas on the proliferation of human uterine leiomyoma cells and the expression of gene related the mechanism of cell apoptosis. Methods : We counted the number of death cells treated with indicated concentration of Millettia Reticulatas and investigated cell death rate by MTS assay. Furthermore, flow cytometry analyis and DNA fragmentation assay were used to dissect between necrosis and apoptosis. and then we observed the differential gene expression by western blot analysis. Results : 1) The inhibitory effect on the growth of uterine leiomyoma cell treated with Millettia Reticulatas was increased in a concentration proportional. 2) The result of flow cytometry analysis. subG1 phase arrest related3 cell apoptosis was investigated 23.49% in uterine leiomyoma cell treated Millettia Reticulatas and showed the fession of proportional concentration. 3) The gene expression of p27, p53, p21, p16 related cell cycle was increased according to increasing concentration but cyclin E was none exchanged. 4) The character of apoptosis, DNA fragmentation was significantly observed the fession of proportional concentration. 5) The expression of pro-caspase3 and PARP were decreased dependent on treatment concentration. Conclusion : This study showed that Millettia Reticulatas have the inhibitory effect on the proliferation of human uterine leiomyoma cell and the effect was related with apoptosis. The apoptotic mechanism was observed that the gene expression of p27, p53, p21, p16 related cell cycle was increased according to increasing treatment concentration, induced G1 phase arrest and finally cell death was occurred. The decreased expression of pro-caspase 3 and PARP were noted that apoptosis was related with caspase pathway.

• Nuclear Engineering and Technology
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• 제28권2호
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• pp.103-117
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• 1996

본 논문에서는 증기폭발의 전파과정을 해석하기 위한 수학적 모델을 제시하였다. 이 모델은 용융물, 용융파편, 그리고 냉각재 기상과 액상 등 4상 유체의 2차원적인 천이거동을 지배방정식 및 관련상관식의 수치적 해를 구함으로서 예측할 수 있다. 모델에 사용된 주요 상관식은 용융물 분쇄, 냉각재 상변화, 에너지 교환, 그리고 운동량 교환항으로 구성되어 있다. 그리고, 냉각재(물)의 상태방정식은 냉각재의 기상과 액상 사이의 열역학적 인 비평형을 허용할 수 있는 독특한 형태로 구성되었다. 주석 /물의 중기폭발에 대한 예제계산을 수행한 결과 본 모델이 폭발의 전파속도 및 압력 -비록 그 정량적인 값은 관련상관식의 인자들에 좌우되지마는- 등의 증기폭발 전파과정의 주요현상을 적절히 모사할 수 있음을 알 수 있었다. 또한 중요한 초기변수(중기 분율, 용융물 분율) 및 관련상관식에 대한 민감도 분석도 수행되었다.

• 대한한방부인과학회지
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• 제19권2호
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• pp.199-213
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• 2006

Purpose : This study was aimed to investigate the inhibitory effect of Sparganii Rhizoma on the proliferation of human uterine leiomyoma cells and the expression of gene related the mechanism of cell apoptosis. Methods : This study was evaluated the number of death cells treated with indicated concentration of Sparganii Rhizoma and investigated cell death rate by MTS assay. Furthermore, fluorescence-activated cell sorter analysis and DNA fragmentation assay were used to dissect between necrosis and apoptosis. and then we observed the differential gene expression by western blot analysis. Results :1) The inhibitory effect on the growth of uterine leiomyoma cell treated with Sparganii Rhizoma was increased in a dose dependent manner. 2) As the result of FACS analysis, subG1 phase incrase was observed 23.49% inuterine leiomyoma cell treated with Sparganii Rhizoma at $500\;{\mu}g/ml$ compared to control.. 3) The gene expression of p53, p21 related cell apoptosis was increased according to increasing concentration but p27 was none exchanged. 4) The expression of cyclin A, D and E was decreased in a concentration proportional and then the dephosphorylation of pRb was increased. 5) The character of apoptosis, DNA fragmentation was significantly observed according to increasing concentration. 6) The expression of pro-caspase3 were decreased dependent on treatment concentration and activated PARP took place. Conclusion : The inhibitory effect of Sparganii Rhizoma on the proliferation of human uterine leiomyoma cells was observed with apoptosis and cell cycle arrest. These data suggest that Sparganii Rhizoma might be candidate of medical therapy for uterine leiomyoma.

• 생명과학회지
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• 제22권11호
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• pp.1435-1443
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• 2012

거제도 안골 골짜기와 뱃골 골짜기에서 식물 군락의 변화를 조사하였다. 알파-다양도와 감마-다양도는 서식지 단절의 크기와 정도에 따라 감소하였다. 우세종의 평균 종수도 서식지 단절에 따라 감소하였다. 상수리나무를 비롯한 참나무과 종들은 붉은토끼풀 같은 도입된 귀화식물의 증가에 따라 주요도가 감소하였다. 교란이 일어나지 않은 숲에서 성체 생존율의 몫이 증가함에 따라 탄력 예상치의 절대적 비는 2003년부터 2011년까지 증가하였다. 그러나 교란 집단에서는 비가 낮았다. Moran의 I값은 전반적으로 서식지 단절지역과 서식지전환 시기에서는 감소하였다. 결국 거제도에서 도시화에 따른 식물 군락은 환경이 교란되었을 때 보편종의 감소를 유발하였다.

• 한국지리정보학회지
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• 제6권3호
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• pp.11-20
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• 2003

최근 부각되고 있는 도시지역의 환경문제 해결을 위해서는 다각적인 접근방법이 요구되는데, 도시지역에 산재해 있는 도시림의 효율적인 관리는 그 방법 중 하나가 될 수 있다. 본 연구에서는 도심지와 인접해 있는 지리적 여건으로 인해 오래전부터 인간의 간섭을 지속적으로 받아온 대구광역시의 앞산자연공원을 대상으로 토지이용 변화 및 경관지수를 사용하여 경관구조 변화에 대해 분석하고자 하였으며, 분석결과를 요약하면 다음과 같다. 첫째, 대상지역의 남쪽으로는 산지연계형의 도시림 특성으로 인해 생태적으로 안정된 환경을 유지하고 있는 반면, 그 외 지역에서는 대구시의 산업화로 인한 이농현상으로 1980년 이전에 도시화가 완료된 것으로 나타났다. 둘째, 경관요소별 면적변화에 따르면, 경작지의 대부분이 도시지역으로 전용된 것으로 나타났으며, 대표적인 경관요소가 소나무림과 농경지에서 혼효림과 도시역으로 변화된 것으로 나타났다. 셋째, 경관지수 분석결과, 조림지에 있어서 인위적인 간섭보다는 산불의 피해임지에 조림된 수종의 조림실패로 인해 활엽수 및 혼효림으로 전환된 것으로 나타났다.

• 대한한방부인과학회지
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• 제18권1호
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• pp.181-191
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• 2005

Purpose : ${\beta}$-sitosterol is kind of phytosterols or plant which are structurally similar to cholesterol. This study was aimed to investigate the inhibitory effect of the ${\beta}$-sitosterol on the proliferation of human uterine leiomyoma cells and the expression of gene related the mechanism of cell apoptosis. Methods : We counted the number of death cells treated with indicated time of the ${\beta}$-sitosterol and investigated cell death rate by cell count assay. Furthermore, flow cytometry analysis and DNA fragmentation assay were used to dissect between necrosis and apoptosis. and then we observed the differential gene expression by western blot analysis. Results : 1) The inhibitory effect on the growth of uterine leiomyoma cell treated with the ${\beta}$-sitosterol $16{\mu}M$ was increased in a time dependent. 2) The result of flow cytometry analysis, subG1 phase arrest related cell apoptosis was investigated 16.97% in uterine leiomyoma cell treated with the ${\beta}$-sitosterol $16{\mu}M$ and showed the fashion of proportional time dependent. 3) The gene expression of p27, p21 related cell cycle was increased according to increasing time interval but cyclin E-CDK2 complex was decreased expression. 4) The character of apoptosis, DNA fragmentation was significantly observed on the time dependent. 5) The expression of pro-caspase 3 and PARP were decreased dependent on treatment with time dependent. Conclusion : This study showed that the ${\beta}$-sitosterol have the inhibitory effect on the proliferation of human uterine leiomyoma cell and the effect was related with apoptosis.

• Clinical and Experimental Reproductive Medicine
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• 제48권1호
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• pp.61-68
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• 2021

Objective: This study was conducted to investigate the relationship of semen parameters in samples used for intracytoplasmic sperm injection (ICSI) with fertilization and pregnancy rates in infertile couples. Methods: In this prospective study of Infertile couples with male factor infertility that had undergone ICSI, fractions of the same semen samples obtained for microinjection (to ensure the best predictability) were evaluated to determine the semen parameters and sperm DNA fragmentation index (DFI) on the day of oocyte recovery. Results: In total, 120 couples completed the study and were subdivided into fertilized (n=87) and non-fertilized couples (n=33). The fertilized couples were further classified into pregnant (n=48) and non-pregnant (n=39) couples. Compared to non-fertilized and non-pregnant couples, fertilized and pregnant couples showed statistically significantly higher sperm viability and percentage of normal sperm morphology, as well as significantly lower sperm DFI values. A receiver operating characteristic curve analysis of data from the 120 ICSI cycles showed that sperm viability, normal sperm morphology percentages, and sperm DFI were significant prognostic indicators of fertilization at cutoff values of 40%, 7%, and 46%, respectively. A sperm DFI of 46% showed sensitivity and specificity of 95% and 90%, respectively, for predicting fertilization, and no clinical pregnancies occurred in couples with a sperm DFI above 46%. Conclusion: Semen parameters from the ICSI day sample, especially sperm viability, normal morphology, and DFI, had an impact on fertilization and pregnancy outcomes in ICSI cycles.

• 한국동물생명공학회지
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• 제36권4호
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• pp.299-306
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• 2021

Vitrification methods are commonly used for mammalian reproduction through the long-term storage of blastocyst produced in vitro. However, the survival and quality of embryos following vitrification are significantly low compared with blastocyst from in vitro production (IVP). This study evaluates that the survival of frozen-thawed bovine embryos was relevant to mitochondrial superoxide derived mitochondrial activity. Here we present supplementation of the cryopreservation medium with Mito-TEMPO (0.1 µM) induced a significant (p < 0.001; non-treated group: 56.8 ± 8.7%, reexpanded at 24 h vs Mito-TEMPO treated group: 77.5 ± 8.9%, re-expanded at 24 h) improvement in survival rate of cryopreserved-thawed bovine blastocyst. To confirm the quality of vitrified blastocyst after thawing, DNA fragmentation of survived embryos was examined by TUNEL assay. As a result, TUNEL positive cells rates of frozen-thawed embryos were lower in the Mito-TEMPO treated group (4.2 ± 1.4%) than the non-treated group (7.1 ± 3.5%). In addition, we investigated the intracellular ROS and mitochondrial specific superoxide production using DCF-DA and Mito-SOX staining in survived bovine embryos following vitrification depending on Mito-TEMPO treatment. As expected, intracellular ROS levels and superoxide production of vitrified blastocysts after cryopreservation were significantly reduced (p < 0.05) according to Mito-TEMPO supplement in freezing medium. Also, mitochondrial activity measured by MitoTracker Orange staining increased in the frozen-thawed embryos with Mito-TEMPO compared with non-treated group. These results indicate that the treatment of Mito-TEMPO during cryopreservation might induce reduction in DNA fragmentation and apoptosis-related ROS production, consequently increasing mitochondrial activation for developmental capacity of frozen-thawed embryos.

• 한국식품영양과학회지
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• 제36권7호
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• pp.819-824
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• 2007

본 연구는 큰비쑥를 80% EtOH로 추출하고 극성에 따른 용매분획을 실시하여 혈핵암 세포주를 대상으로 분획별에 따른 암세포 증식억제(cytotoxicity) 효과와 이러한 혈액암 세포주에 대한 세포독성 효과가 세포자연사(apoptosis)에 의해 일어나는 것인지, 몇 가지 apoptosis 유도 실험을 통해 확인해 보았다. HL-60 세포에 대한 증식억제 효과는 전반적으로 모든 처리구에서 농도의존적인 세포증식 억제효과가 나타났으며, 특히 헥산과 디클로로메탄 분획물에서 가장 강한 세포성장 억제효과가 나타났다. 이러한 세포성장 억제효과가 apoptosis 유도에 의한 것인지 알아보기 위해 apoptosis 유도에 의한 세포사멸의 특징인 DNA 단편화 현상을 비롯하여 세포형태학적 변화 및 유동세포분석기를 통한 DNA content를 측정한 결과, 큰비쑥 추출물에 의한 암세포 증식억제효과는 apoptosis를 유도하여 세포자연사를 통해 세포의 성장을 억제하는 것으로 확인되었다.