• Journal of Life Science
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• v.34 no.6
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• pp.418-425
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• 2024

Solid tumors are heterogeneous populations of multiple cell types. While the majority of the cells that comprise cancer are unable to divide, cancer stem cells have self-renewal and differentiation properties. Normal stem cell pathways that control self-renewal are overactivated in cancer stem cells, making cancer stem cells important for cancer cell expansion and progression. Dick first proposed the definition of cancer stem cells in acute myeloid leukemia, according to which cancer stem cells can be classified based on the expression of cell surface markers. Cancer stem cells maintain their potential in the tumor microenvironment. Multiple cell types in the tumor microenvironment maintain quiescent cancer stem cells and serve as regulators of cancer growth. Since current cancer treatments target proliferative cells, quiescent state cancer stem cells that are resistant to treatment increase the risk of recurrence or metastasis. Various signals of the tumor microenvironment induce changes to become a tumor-supportive environment by remodeling the vasculature and extracellular matrix. To effectively treat cancer, cancer stem cells and the tumor microenvironment must be targeted. Therefore, it is important to understand how the tumor microenvironment induces reprogramming of the immune response to promote cancer growth, immune resistance, and metastasis. In this review, we discuss the cellular and molecular mechanisms that can enhance immunosuppression in the tumor microenvironment.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06a
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• pp.37-39
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• 2006

지지 벡터 기계(Support Vector Machine; SVM)는 기본적으로 이진분류를 위해 고안되었지만, 최근 다양한 분류기 생성전략과 결합전략이 고안되어 다중부류 분류에도 적용되고 있다. 본 논문에서는 OVR(One-Vs-Rest) 전략으로 생성된 SVM을 NB(Naive Bayes) 분류기를 이용하여 동적으로 구성함으로써, OVR SVM을 이용한 다중부류 분류 시스템에서 자주 발생하는 동점을 효과적으로 해결하는 방법은 제안한다. 이 방법을 유전발현 데이터를 이용한 다중부류 암 분류에 적용하였는데, 고차원의 데이터로부터 NB 분류기 구축에 유용한 유전자를 선택하기 위해 Pearson 상관계수를 사용하였다. 14개의 암 유형과 16,063개의 유전발현 수준을 가지는 대표적인 다중부류 암 분류 데이터인 GCM 암 데이터에 적용하여 제안하는 방법의 유용성을 확인하였다.

• Composites Research
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• v.35 no.5
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• pp.303-308
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• 2022

PIC (Piecewise Integrated Composite) is a new concept for designing a composite structure with mosaically assigning various types of stacking sequences in order to improve mechanical properties of laminated composites. Also, machine learning is a sub-category of artificial intelligence, that refers to the process by which computers develop the ability to continuously learn from and make predictions based on data, then make adjustments without further programming. In the present study, the tapered box beam type PIC robot arm for carrying and transferring wide and thin LCD display was designed based on the machine learning in order to increase structural stiffness. Essential training data were collected from the reference elements, which were intentionally designated elements among finite element models, during preliminary FE analysis. Additionally, triaxiality values for each finite element were obtained for judging the dominant external loading type, such as tensile, compressive or shear. Training and evaluating machine learning model were conducted using the training data and loading types of elements were predicted in case the level accuracy was fulfilled. Three types of stacking sequences, which were to be known as robust toward specific loading types, were mosaically assigned to the PIC robot arm. Henceforth, the bending type FE analysis was carried out and its result claimed that the PIC robot arm showed increased stiffness compared to conventional uni-stacking sequence type composite robot arm.

• Journal of Radiation Protection and Research
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• v.31 no.2
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• pp.53-63
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• 2006

The increased risk of cancer with exposure to low-dose radiation was estimated through longitudinal study for radiation workers at the nuclear power plants in Korea. The radiation dose data were collected from the Radiation Safety Management System(RSMS) of the Korea Hydro & Nuclear Power Co., Ltd(KHNP). The cancer risks with radiation exposure were evaluated in terms of relative mortality ratios(RMR) and relative incidence ratios(RIR) to the unexposed employees at the nuclear power plants, and of the standardized mortality ratios(SMR) and standardized incidence ratios(SIR). There were no significant increases of canters of all sites in the exposed group either in RIR[1.08, 95% confidence interval(CI) 0.74-1.58] or in RMR[1.21, CI 0.70-2.08]. Neither SIR[0.81, CI 0.28-0.96] nor SMR[0.86, CI 0.66-1.10] significantly deviated from 1.0 for cancers of all sites. The trend analysis did not identify evident dose-response relationship due to insufficient numbers of the cases. Consequently, it is concluded that increases in cancer risks in the radiation worker group exposed to low doses at the nuclear power plants in Korea are not identified at this time.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.58-58
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• 1992

연구자들은 제 2상 임상시험의 모델을 검토하기 위하여, 비무작위적 제 2상 임상시험을 진행 위선암환자에서 시행하였다. 병리조직학적으로 확인되고, 객관적으로 계측가능 병변이 있는 위선암 환자를 대상으로 하였으며, 위선암의 조직 진단은 위선암의 모든 유형을 포함하였다. 환자는 (Datelliptinium)율 1일 250 mg/$m^2$씩 3일 연속 30분에 걸쳐 정주하고, 매 3주마다 반복하였다. 반응의 완전평가는 초치료전 실시하여, 14-25명의 환자가 포함될 예정으로 시작하여 총 15명의 환자가 포함되었다. 매 환자마다 매 치료 주기전에 평가를 실시하였다. 최소 1주기 (3일 치료)를 끝낸 환자에서도 반응평가가 가능한 것으로 간주하였으며 치료기간은 반응의 정도와 치료에 대한 내약력으로 결정하였고, 만일 치료에 대해 현저한 독성이 발생되지 않는다면, 치료 반응이 계속되는 동안 약물투여를 계속하였다. 국소진행암의 경우 약물의 반응이 현저하고, 환자의 전신상태가 현저히 개선되어 외과적 절제가 가능하면, 관해로 간주하고 외과적 절제를 실시 후 약물은 4회 투여하고 치료 종료 후 추적 관찰할 계획으로 시행하였다.

• 대한핵의학회:학술대회논문집
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• 1990.04a
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• pp.206.1-206.1
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• 1990

• Radioisotope journal
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• v.12 no.2
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• pp.40-45
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• 1997

• 대한핵의학회:학술대회논문집
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• 1976.06a
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• pp.70.3-71
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• 1976

• Journal of Nutrition and Health
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• v.53 no.5
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• pp.532-546
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• 2020

Purpose: Although the number of cancer survivors is increasing because of early diagnosis and better treatment, they are worried about relapses and metastasis. This study examined the dietary safety management awareness, capacity, and behavior of cancer survivors. Methods: Data were collected from 233 cancer survivors in Daegu and Gyeongbuk areas using a self-administered 5-Likert questionnaire from March to May 2018. Frequency analysis, one-way analysis of variance, factor analysis, reliability analysis, and correlation analysis were analyzed using the SPSS. Results: The average score for each factor was as follows: importance of weight management (3.83), education requirement (3.79), unhealthy diet (reverse, 3.64), food safety anxiety (3.34), lack of awareness of over and malnutrition (reverse, 3.26), obsession (3.23), cooking capacity (3.16), health-function pursuit (3.04), balanced diet (2.93), and chronic disease anxiety (2.64). The average dietary safety competency factors were significantly lower among the male survivors, aged 60-80 years, lower economic condition, and less nutritional supplement intake. Female survivors comprised the highest proportion with high health management and cooking capacity, while men had the lowest of all the factors (p < 0.001). The group that was low in all three capacity factors had a significantly lower average score of difficulty in acquiring knowledge (reverse), lack of awareness of over- and malnutrition (reverse), importance of weight management, education requirement, knowledge, balanced diet, and health-functional pursuit compared to the other groups (p < 0.001). Conclusion: To effectively manage health, dietary safety management education should be differentiated and actively conducted according to sex, age, cancer diagnosis time, economic status, nutritional supplement intake, and the capacity cluster of cancer survivors.

• Korean Journal of Clinical Laboratory Science
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• v.55 no.2
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• pp.93-104
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• 2023

This study aimed to identify new markers that cause lung adenocarcinoma by analyzing mutation hotspots for the top five genes with high mutation frequency in lung adenocarcinoma in Koreans by next generation sequencing (NGS) analysis. The association between TP53 mutation types and patterns with smoking, a major cause of lung cancer, was examined. The clinicopathological characteristics of lung adenocarcinoma patients with TP53 P72R SNPs were analyzed. In Korean lung adenocarcinoma cases, regardless of the smoking status, the TP53 P72R SNP was the most frequently occurring mutational hotspot, in which the nucleotide base was transversed from C to G, and the amino acid was substituted from proline to arginine at codon 72 of TP53. An analysis of the clinicopathological characteristics of lung adenocarcinoma cases with TP53 P72R SNP revealed no significant correlation with the patient's age, gender, smoking status, and tumor differentiation, but a significant correlation with low stage (P-value =0.026). This study confirmed an increase in TP53 rather than EGFR, which was reported as the most frequent mutations in lung adenocarcinoma in Koreans through NGS. Among them, TP53 P72R SNP is the most frequent regardless of smoking status.