• 농업생명과학연구
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• 제46권6호
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• pp.33-41
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• 2012

본 연구는 덕유산, 계방산의 가문비나무 군락의 보존을 위한 기초자료를 제시하기 위하여 종조성과 흉고직경급을 조사, 분석하였다. 두 조사지의 교목 아교목 관목층의 층위별 식생은 덕유산이 8, 20, 26종, 계방산이 12, 23, 33종으로 구성되어 있다. 층위별 중요치 분석 결과, 덕유산 교목층은 가문비나무, 사스래나무, 구상나무, 아교목층은 사스래나무, 신갈나무, 관목층은 조릿대가 중요치가 높았으며, 계방산의 교목층은 가문비나무, 사스래나무, 분비나무, 아교목층은 시닥나무, 부게꽃나무, 관목층은 미역줄나무의 중요치가 가장 높은 것으로 분석되었다. 조사구의 층위별 종다양도의 경우 교목층은 덕유산 0.779, 계방산 0.984, 아교목층은 덕유산 1.052, 게방산 1.161, 관목층은 덕유산 0.823, 계방산 1.304로 분석되었다. 흉고직경 분포에서는 덕유산지역의 가문비나무 개체군이 역J형의 유형이 나타나고 있어 당분간 가문비나무군락이 유지될 수 있을 것으로 판단된다.

• 고려인삼학회:학술대회논문집
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• 고려인삼학회 2002년도 학술대회지
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• pp.129-144
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• 2002

We investigated anti-hyperglycemic and anti-obese effects of Panax ginseng berry extract and its major constituent, ginsenoside Re, in obese diabetic C57BL/6J ob/ob mice and their lean littermates. Animals received daily intraperitoneal injections of Panax ginseng berry extract for 12 days. On Day 5, 150 mg/kg extract-treated ob/ob mice had significantly lower fasting blood glucose levels compared to vehicle-treated mice $(156{\pm}9.0\;mg/dl\;vs.\;243{\pm}15.8mg/dl,$ P<0.01). On Day 12, the extract-treated ob/ob mice became normoglycemic $(137{\pm}6.7\;mg/dl)$ and had significantly improved glucose tolerance. The overall glucose excursion during the two-hour intraperitoneal glucose tolerance test (IPGTT), calculated as area under the curve (AUC), decreased by $46\%$ (P<0.01) compared to vehicle-treated ob/ob mice. Glucose levels of lean mice were not significantly affected by the extract. The improvement in blood glucose levels in 150 mg/kg extracttreated ob/ob mice was associated with significant reduction in serum insulin levels of fed and fasting mice. Consistent with an improvement in insulin sensitivity, hyperinsulinemic euglycemic clamp study revealed a more than 2-fold increase in the rate of insulin-stimulated glucose disposal in treated ob/ob mice $(112{\pm}19.1\;vs.\;52{\pm}11.8{\mu}mol/kg/min$ for the vehicle group, P<0.01). In addition, 150 mg/kg extract-treated ob/ob mice, but not the lean mice, lost significant weight (from $51.7{\pm}1.9g\;on\;Day\;0\;to\;45.7{\pm}1.2$ on Day 12, P<0.01 compared to vehicle-treated ob/ob mice), associated with a significant reduction in food intake (P<0.05) and a very significant increase in energy expenditure (P<0.01) and body temperature (P<0.01). A 12-day treatment with 150 mg/kg Panax ginseng berry extract also significantly reduced plasma cholesterol levels in ob/ob mice. Additional studies demonstrated that ginsenoside Re, a major constituent of the ginseng berry, but not from the root, plays a significant role in anti-hyperglycemic action. This anti-diabetic effect of ginsenoside Re was not associated with body weight changes, suggesting that other constituents in the extract have distinct pharmacological mechanisms on energy metabolism. The identification of a significant anti-hyperglycemic activity in ginsenoside Re may provide an opportunity to develop a novel class of anti-diabetic agent.

• Journal of Ginseng Research
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• 제43권3호
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• pp.460-474
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• 2019

Background: Ginsenoside compound K (CK) is a promising drug candidate for rheumatoid arthritis. This study examined the impact of polymorphisms in NR1I2, adenosine triphosphate-binding cassette (ABC) transporter genes on the pharmacokinetics of CK in healthy Chinese individuals. Methods: Forty-two targeted variants in seven genes were genotyped in 54 participants using Sequenom MassARRAY system to investigate their association with major pharmacokinetic parameters of CK and its metabolite 20(S)-protopanaxadiol (PPD). Subsequently, molecular docking was simulated using the AutoDock Vina program. Results: ABCC4 rs1751034 TT and rs1189437 TT were associated with increased exposure of CK and decreased exposure of 20(S)-PPD, whereas CFTR rs4148688 heterozygous carriers had the lowest maximum concentration ($C_{max}$) of CK. The area under the curve from zero to the time of the last quantifiable concentration ($AUC_{last}$) of CK was decreased in NR1I2 rs1464602 and rs2472682 homozygous carriers, while $C_{max}$ was significantly reduced only in rs2472682. ABCC4 rs1151471 and CFTR rs2283054 influenced the pharmacokinetics of 20(S)-PPD. In addition, several variations in ABCC2, ABCC4, CFTR, and NR1I2 had minor effects on the pharmacokinetics of CK. Quality of the best homology model of multidrug resistance protein 4 (MRP4) was assessed, and the ligand interaction plot showed the mode of interaction of CK with different MRP4 residues. Conlusion: ABCC4 rs1751034 and rs1189437 affected the pharmacokinetics of both CK and 20(S)-PPD. NR1I2 rs1464602 and rs2472682 were only associated with the pharmacokinetics of CK. Thus, these hereditary variances could partly explain the interindividual differences in the pharmacokinetics of CK.

• Journal of Nutrition and Health
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• 제54권6호
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• pp.594-602
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• 2021

본 연구는 고지방식이로 유도한 비만 동물모델에서 아연의 식이를 통한 보충 급여가 혈당 조절과 골격 근육의 ZIP7의 작용에 미치는 영향에 대해 살펴보았다. 고지방식이를 공급한 HF군은 정상 대조군에 비하여 단위 체중당 골격 근육 무게가 유의하게 감소하였으며, 혈당은 유의적으로 증가하였다. 고지방식이와 함께 아연을 보충 공급한 HF+Zn군은 아연을 보충하지 않은 HF군과 비교하여, 공복 혈당과 경구 포도당 부하 후 혈당 증가 면적이 유의하게 감소하였다. 또한, HF+Zn군은 HF군에 비해 골격 근육의 ZIP7 단백질 수준이 유의하게 증가하였으며, AKT 활성과 GLUT4 단백질 수준도 유의하게 증가하는 것으로 나타났다. 이상의 결과를 종합해 볼 때, 아연 보충은 비만으로 인한 고혈당 증세를 완화하는 효과를 나타내며, 이는 골격 근육에서의 ZIP7 아연 수송체에 의한 당 대사 조절과 관련이 있을 것으로 생각된다.

• Journal of Gastric Cancer
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• 제21권4호
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• pp.368-378
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• 2021

Purpose: When patients with early gastric cancer (EGC) undergo non-curative endoscopic submucosal dissection requiring gastrectomy (NC-ESD-RG), additional medical resources and expenses are required for surgery. To reduce this burden, predictive model for NC-ESD-RG is required. Materials and Methods: Data from 2,997 patients undergoing ESD for 3,127 forceps biopsy-proven differentiated-type EGCs (2,345 and 782 in training and validation sets, respectively) were reviewed. Using the training set, the logistic stepwise regression analysis determined the independent predictors of NC-ESD-RG (NC-ESD other than cases with lateral resection margin involvement or piecemeal resection as the only non-curative factor). Using these predictors, a risk-scoring system for predicting NC-ESD-RG was developed. Performance of the predictive model was examined internally with the validation set. Results: Rate of NC-ESD-RG was 17.3%. Independent pre-ESD predictors for NC-ESD-RG included moderately differentiated or papillary EGC, large tumor size, proximal tumor location, lesion at greater curvature, elevated or depressed morphology, and presence of ulcers. A risk-score was assigned to each predictor of NC-ESD-RG. The area under the receiver operating characteristic curve for predicting NC-ESD-RG was 0.672 in both training and validation sets. A risk-score of 5 points was the optimal cut-off value for predicting NC-ESD-RG, and the overall accuracy was 72.7%. As the total risk score increased, the predicted risk for NC-ESD-RG increased from 3.8% to 72.6%. Conclusions: We developed and validated a risk-scoring system for predicting NC-ESD-RG based on pre-ESD variables. Our risk-scoring system can facilitate informed consent and decision-making for preoperative treatment selection between ESD and surgery in patients with EGC.

• Nuclear Engineering and Technology
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• 제54권2호
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• pp.479-485
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• 2022

At the Korea Institute of Radiological and Medical Sciences, physical human phantoms were developed to evaluate various radiation protection quantities, based on the mesh-type reference computational phantoms of the International Commission on Radiological Protection. The physical human phantoms were fabricated such that a radiophotoluminescent glass dosimeter (RPLGD) with a Tin filter, namely GD-352M, could be inserted into them. A Tin filter is used to eliminate the overestimated signals in low-energy photons below 100 keV. The measurement uncertainty of the RPLGD reader system based on GD-352M should be analyzed for obtaining reliable protection quantities before using it for practical applications. Generally, the measurement uncertainty of RPLGD systems without Tin filters is analyzed for quality assurance of radiotherapy units using a high-energy photon beam. However, in this study, the measurement uncertainty of GD-352M was analyzed for evaluating the protection quantities. The measurement uncertainty factors in the RPLGD include the reference irradiation, regression curve, reproducibility, uniformity, energy dependence, and angular dependence, as described by the International Organization for Standardization (ISO). These factors were calculated using the Guide to the Expression of Uncertainty in Measurement method, applying ISO/ASTM standards 51261(2013), 51707(2015), and SS-ISO 22127(2019). The measurement uncertainties of the RPLGD reader system with a coverage factor of k = 2 were calculated to be 9.26% from 0.005 to 1 Gy and 8.16% from 1 to 10 Gy. A blind test was conducted to validate the RPLGD reader system, which demonstrated that the readout doses included blind doses of 0.1, 1, 2, and 5 Gy. Overall, the E_n values were considered satisfactory.

• 천문학회지
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• 제55권4호
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• pp.123-130
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• 2022

We present the analysis of a planetary microlensing event OGLE-2019-BLG-0362 with a shortduration anomaly (~0.4 days) near the peak of the light curve, which is caused by the resonant caustic. The event has a severe degeneracy with ∆𝜒² = 0.9 between the close and the wide binary lens models both with planet-host mass ratio q ≃ 0.007. We measure the angular Einstein radius but not the microlens parallax, and thus we perform a Bayesian analysis to estimate the physical parameters of the lens. We find that the OGLE-2019-BLG-0362L system is a super-Jovian-mass planet $M_p=3.26^{+0.83}_{-0.58}M_J $ orbiting an M dwarf $M_h=0.42^{+0.34}_{-0.23}M_{\odot}$ at a distance $D_L=5.83^{+1.04}_{-1.55}kpc$. The projected star-planet separation is ${\alpha}_{\bot}= 2.18^{+0.58}_{-0.72}AU$, which indicates that the planet lies beyond the snow line of the host star.

• Nuclear Engineering and Technology
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• 제26권3호
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• pp.401-410
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• 1994

실험실 규모의 인공균열 추적자 이동실험을 통해 지하매질의 단일균열을 위한 핵종이동 모델중 수리 분산확산모델 및 국부통로확산모델의 타당성이 연구되었다. 사용된 추적자는 비수착성으로 알려진 우라닌과 소디움 리그노설포네이트 이었으며 적용유량은 0.4에서 1.5cc /min의 범위였다. 최적화법으로 모델들의 관련 매개변수들을 구하였으며 모델과 실험결과를 비교하였다. 실험에서 우라닌은 암석내로의 확산이 중요한 인자임을 보여주었고, 두 물질 모두 균열 표면에서의 수착은 중요하게 작용하지 않았다. 두 모델의 암석 확산을 나타내는 매개변수값들은 서로 잘 일치하였다. 모사결과에 따르면 유량변화시 두 모델은 정량적으로 같은 결과를 주었으나, 균열길이는 다른 크기로 두 모델에 영향을 주었다. 즉, 균열길이가 커짐에 따라 국부통로화산모델의 파과곡선 퍼짐성 (dispersivity)이 수리분산화산모델의 파과곡선 퍼짐성보다 증가하였다. 실험과 모델들의 일치는 위 두모델들이 단일 균열 시스템을 해석하는데 매우 유용함을 입증하였다.

• Korean Journal of Radiology
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• 제22권7호
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• pp.1213-1224
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• 2021

Objective: To develop a machine learning (ML) pipeline based on radiomics to predict Coronavirus Disease 2019 (COVID-19) severity and the future deterioration to critical illness using CT and clinical variables. Materials and Methods: Clinical data were collected from 981 patients from a multi-institutional international cohort with real-time polymerase chain reaction-confirmed COVID-19. Radiomics features were extracted from chest CT of the patients. The data of the cohort were randomly divided into training, validation, and test sets using a 7:1:2 ratio. A ML pipeline consisting of a model to predict severity and time-to-event model to predict progression to critical illness were trained on radiomics features and clinical variables. The receiver operating characteristic area under the curve (ROC-AUC), concordance index (C-index), and time-dependent ROC-AUC were calculated to determine model performance, which was compared with consensus CT severity scores obtained by visual interpretation by radiologists. Results: Among 981 patients with confirmed COVID-19, 274 patients developed critical illness. Radiomics features and clinical variables resulted in the best performance for the prediction of disease severity with a highest test ROC-AUC of 0.76 compared with 0.70 (0.76 vs. 0.70, p = 0.023) for visual CT severity score and clinical variables. The progression prediction model achieved a test C-index of 0.868 when it was based on the combination of CT radiomics and clinical variables compared with 0.767 when based on CT radiomics features alone (p < 0.001), 0.847 when based on clinical variables alone (p = 0.110), and 0.860 when based on the combination of visual CT severity scores and clinical variables (p = 0.549). Furthermore, the model based on the combination of CT radiomics and clinical variables achieved time-dependent ROC-AUCs of 0.897, 0.933, and 0.927 for the prediction of progression risks at 3, 5 and 7 days, respectively. Conclusion: CT radiomics features combined with clinical variables were predictive of COVID-19 severity and progression to critical illness with fairly high accuracy.

• Korean Journal of Radiology
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• 제22권5호
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• pp.697-705
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• 2021

Objective: To investigate the feasibility and the accuracy of the coronary CT angiography (CCTA)-derived Registry of Crossboss and Hybrid procedures in France, the Netherlands, Belgium and United Kingdom (RECHARGE) score (RECHARGECCTA) for the prediction of procedural success and 30-minutes guidewire crossing in percutaneous coronary intervention (PCI) for chronic total occlusion (CTO). Materials and Methods: One hundred and twenty-four consecutive patients (mean age, 54 years; 79% male) with 131 CTO lesions who underwent CCTA before catheter angiography (CA) with CTO-PCI were retrospectively enrolled in this study. The RECHARGECCTA scores were calculated and compared with RECHARGECA and other CTA-based prediction scores, including Multicenter CTO Registry of Japan (J-CTO), CT Registry of CTO Revascularisation (CT-RECTOR), and Korean Multicenter CTO CT Registry (KCCT) scores. Results: The procedural success rate of the CTO-PCI procedures was 72%, and 61% of cases achieved the 30-minutes wire crossing. No significant difference was observed between the RECHARGECCTA score and the RECHARGECA score for procedural success (median 2 vs. median 2, p = 0.084). However, the RECHARGECCTA score was higher than the RECHARGECA score for the 30-minutes wire crossing (median 2 vs. median 1.5, p = 0.001). The areas under the curve (AUCs) of the RECHARGECCTA and RECHARGECA scores for predicting procedural success showed no statistical significance (0.718 vs. 0.757, p = 0.655). The sensitivity, specificity, positive predictive value, and the negative predictive value of the RECHARGECCTA scores of ≤ 2 for predictive procedural success were 78%, 60%, 43%, and 87%, respectively. The RECHARGECCTA score showed a discriminative performance that was comparable to those of the other CTA-based prediction scores (AUC = 0.718 vs. 0.665-0.717, all p > 0.05). Conclusion: The non-invasive RECHARGECCTA score performs better than the invasive determination for the prediction of the 30-minutes wire crossing of CTO-PCI. However, the RECHARGECCTA score may not replace other CTA-based prediction scores for predicting CTO-PCI success.