• Journal of Life Science
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• v.29 no.4
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• pp.499-508
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• 2019

Cancer stem cells (CSCs), which are primarily responsible for metastasis and recurrence, have self-renewal, differentiation, therapeutic resistance, and tumor formation abilities. Numerous studies have demonstrated the signaling pathways essential for the acquisition and maintenance of CSC characteristics, such as WNT/${\beta}$-catenin, Hedgehog, Notch, B lymphoma Mo-MLV insertion region 1 homolog (BMI1), Bone morphogenetic protein (BMP), and TGF-${\beta}$ signals. However, few therapeutic strategies have been developed that can selectively eliminate CSCs. Recently, neutralizing antibodies against Cytotoxic T-lymphocyte associated protein 4 (CTLA-4) and Programmed cell death protein 1 (PD-1)/Programmed death-ligand 1 (PD-L1), immune checkpoint inhibitors (ICIs), have shown promising outcomes in clinical trials of melanoma, lung cancer, and pancreatic cancer, as well as in hematologic malignancies. ICIs are considered to outperform conventional anticancer drugs by maintaining long-lasting anti-cancer effects, with less severe side effects. Several studies reported that ICIs successfully blocked CSC properties in head and neck squamous carcinomas, melanomas, and breast cancer. Together, these findings suggest that novel and effective anticancer therapeutic modalities using ICIs for selective elimination of CSCs may be developed in the near future. In this review, we highlight the origin and characteristics of CSCs, together with critical signaling pathways. We also describe progress in ICI-mediated anticancer treatment to date and present perspectives on the development of CSC-targeting ICIs.

• Journal of the Korean Society of Radiology
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• v.4 no.4
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• pp.29-32
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• 2010

The neutron capture cross section of $^{197}Au$ has been measured relative to the $^{10}B(n,{\gamma})$ standard cross section by the neutron time-of-flight(TOF) method using a 46-MeV electron linear accelerator(linac) at the Research Reactor Institute, Kyoto University(KURRI). In order to experimentally prove the result obtained, the supplementary cross section measurement has been made from 0.1 eV to 10 keV using the Kyoto University Lead slowing-down spectrometer (KULS) coupling to the linac. The relative measurement by the TOF method has been normalized to the reference value(24.5 b) at 1 eV. The evaluated capture cross sections in JENDL/D-99 Dosimetry have been compared with the current measurements by the KULS experiments.

• Biomedical Science Letters
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• v.2 no.2
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• pp.257-265
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• 1996

Simple stain and electron microscopic in situ hybridization is studied and applied for the identification of rabbit haemorrhagic disease viral RNA in a unicrylated preparation of the liver after innoculation of rabbit haemorrhagic disease virus. Hybridization for detection of viral RNA in unicryl embedded tissues using complementary 84 bases oligonucleotide probe labelled by biotin CE-phosphoramidite compared with 4717∼4800 sequences of rabbit haemorrhagic disease virus, modified hybridization protocol and antibiotin antibody-l0nm gold as signal marker. The best results were obtained in 0.02% glutaraldehyde, Unicryl resin cell block, biotinylated oligonucleotide probes, antibiotin-l0nm gold. In this report, RHD viral RNA was distributed widely within the mitochondria and nucleus of liver cell by electron microscopic in situ hybridization. In situ hybridization has become a standard method for localizing DNA or RNA sequences in tissue or celt preparation. In situ hybridization is detected the virus genome in the cells and tissue as specifically compared with others nucleic acid hybridization method.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.42 no.1
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• pp.143-150
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• 2019

We focus on the weapon target assignment and fire scheduling problem (WTAFSP) with the objective of minimizing the makespan, i.e., the latest completion time of a given set of firing operations. In this study, we assume that there are m available weapons to fire at n targets (> m). The artillery attack operation consists of two steps of sequential procedure : assignment of weapons to the targets; and scheduling firing operations against the targets that are assigned to each weapon. This problem is a combination of weapon target assignment problem (WTAP) and fire scheduling problem (FSP). To solve this problem, we define the problem with a mixed integer programming model. Then, we develop exact algorithms based on a dynamic programming technique. Also, we suggest how to find lower bounds and upper bounds to a given problem. To evaluate the performance of developed exact algorithms, computational experiments are performed on randomly generated problems. From the results, we can see suggested exact algorithm solves problems of a medium size within a reasonable amount of computation time. Also, the results show that the computation time required for suggested exact algorithm can be seen to increase rapidly as the problem size grows. We report the result with analysis and give directions for future research for this study. This study is meaningful in that it suggests an exact algorithm for a more realistic problem than existing researches. Also, this study can provide a basis for developing algorithms that can solve larger size problems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.3
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• pp.233-240
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• 2018

Radar cross section (RCS) analysis of chaff clouds is essential for the accurate detection and tracking of missile targets using radar. For this purpose, we compare the performance of two existing methods of predicting RCS of chaff clouds. One method involves summing up the RCS values of individual chaffs in a cloud, while the other method predicts the RCS values using aerodynamic models based on the probability density function. In order to compare and analyze the two techniques more precisely, the RCS of a single chaff computer-aided design model consisting of a half wavelength dipole was calculated using the commercial electromagnetic numerical analysis software, FEKO 7.0, to estimate the RCS values of chaff clouds via simulation. Thus, we verified that our method using the probability density distribution model is capable of analyzing the RCS of chaff clouds more efficiently.

• Radiation Oncology Journal
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• v.24 no.2
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• pp.88-95
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• 2006

Purpose: We evaluated whether Cyberknife radiosurgery is an effective and safe method of therapy for medically intractable trigeminal neuralgia (TN). Materials and Methods: We retrospectively analyzed the outcome of 26 patients, who failed to surgery or were not suitable candidates for invasive intervention and were treated by Cyberknife radiosurgery between March 2004 and May 2005. Radiosurgery doses of $60{\sim}64 Gy$ were delivered to the 80% isodose line prescribed to an 6 mm length of the nerve, sparing the most proximal 3 mm away from the trigeminal nerve root entry zone (median dose: 64 Gy). Results: Follow-up period was $3{\sim}15$ months (median follow-up period: 9 months) Preliminary results from a cohort of 26 patients undergoing Cyberknife radiosurgery for TN showed that pain relief was achieved in 50% (13/26) of patients within the first 24 hrs after treatment. At last follow-up, 96.2% (25/26) of patients reported early pain relief within 7 days. Treatment failure developed in 2 of 26. Poor response occurred in one patient and relapse was observed in the other patient. 3 patients had hypoesthesia (11.5%), which was the only complication observed with any of our patients. Conclusion: With these results, authors assumed that Cyberknife radiosurgery for TN could be one of safe and effective therapeutic methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.197-208
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• 2017

The purpose of this study was to construct and test a structural equation model for college student's gambling behavior. A structured questionnaire was completed by 246 college students to analyze the relationships between perspective factors(irrational gambling belief), psychological factors(depression, anxiety), social factors(parental monitoring, parental support, friend support), self-control and gambling behavior. The moderating effects of gender, friends and family's gambling behaviors were examined. The data were analyzed using SPSS 21,0 and AMOS 20.0 programs. Self-control and psychological factors directly affected the college student's gambling behavior, while perspective factors and social factors affected it indirectly. The model fit indices of the modified model were suitable for the recommended levels. The overall study findings suggest the need to develop a gambling prevention program for college students that reinforces self-control, parental monitoring and support, and friend support while reducing irrational gambling belief, depression, and anxiety. An approach that considers gender and a development of a group counseling program for family or friends are also required.

• Journal of Korean Ophthalmic Optics Society
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• v.8 no.2
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• pp.135-151
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• 2003

This study compared the effect of Polaroid$^{(R)}$ lenses on binocular vision by assessing visual acuity, stereopsis, and visual evoked potential(VEP), through Polaroid$^{(R)}$, CR 39 and sunglass lenses. The spectral absorptions of Polaroid$^{(R)}$, CR 39 and sunglass lenses were measured using a spectrophotometer (Hitachi. U-3501). The VEP were recorded by the Nicolet system. Thirty normal adult(fifteen males, fifteen females, mean=21.9 years, range=20 to 25) subjects were recorded. The subjects were provided a history including : general health, family health, medication, genetics, allergy and disease. All had normal or corrected to normal acuity with no history of visual disorders. Corrected visual acuity, colour vision and stereopsis were recorded for each subject monocularly and binocularly. Each test was repealed through the sunglass, CR 39, and Polaroid$^{(R)}$ lenses. Subjects viewed the VEP stimulus both monocularly and binocularly through the test lenses while the VEPs were recorded. The results suggest that the binocular visual acuity and stereoacuity is better than with monocular vision. On other hand, the analysis of VEP suggests that the amplitude of wave is smaller when the monocular eye receives the VEP stimulus compared with that when the binocular eye is stimulated by the VEP target with the sunglass, CR 39, and Polaroid$^{(R)}$ lens. But, the latency period of each eye was similar to results between the dominant eye and the non-dominant eye by the CR 39, sunglass, and polaroid lens. In conclusion, this study indicates that the binocular vision appears to be better through the brown Polaroid$^{(R)}$ lens than through the other test lenses.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.3
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• pp.1964-1971
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• 2015

Human bone marrow or human umbilical cord vein derived-mesenchymal stem cells (hBM-MSCs or hUC-MSCs) have known as a potentially useful cell type for clinical therapeutic applications. We investigated two-pore domain potassium (K2P) channels in these cells. K2P channels play a major role in setting the resting membrane potential in many cell types. Among them, TREK1 is targets of hydrogen, hypoxia, polyunsaturated fatty acids, antidepressant, and neurotransmitters. We investigated whether hBM-MSCs and hUC-MSCs express functional TREK1 channel using RT-PCR analysis and patch clamp technique. Potassium channel with a single channel conductance of 100 pS was found in hUC-MSCs and BM-MSCs and the channel was activated by membrane stretch (-5 mmHg ~ -15 mmHg), arachidonic acid ($10{\mu}M$) and intracellular acidosis (pH 6.0). These electrophysiological properties were similar to those of TREK1. Our results suggest that TREK1 is functionally present in hBM-MSCs and hUC-MSCs, where they contribute to its resting membrane potential.

• Proceedings of the Korea Information Processing Society Conference
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• 2002.11c
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• pp.1871-1874
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• 2002

최근 인터넷 환경에서 지리 정보 서비스를 제공받으려는 사용자들의 지속적인 증가로 인해 저비용의 여러 개의 단일 노드를 고속의 네트워크로 연결하여 고성능을 제공하는 클러스터 기반의 공간 데이터베이스에 대한 연구가 활발하게 진행되고 있다. 이러한 공간 데이터베이스 클러스터에서 사용자가 요구한 공간 질의를 빠르게 처리하기 위해서는 고비용의 공간 조인 연산을 효율적으로 처리하기 위한 기법이 요구된다. 본 논문에서는 비공유 공간 데이터베이스 클러스터 환경하에서 공간 조인 연산 수행 시 효율적인 병렬 처리를 위한 영역 분할 기법 및 병렬 공간 조인 기법을 제안한다. 기존의 병렬 공간 데이터베이스 시스템에서의 분할 기반 병렬 공간 조인 기법들은 병렬로 수행할 작업 분배 및 할당과 분할 경계선 상에 존재하는 공간 객체들에 대한 중복 조인 연산 및 중복 결과 제거 등의 추가적인 연산을 해야 한다는 문제점들이 있다. 제안된 기법은 공간 릴레이션들을 일정 영역들로 분할하여 비공유 공간 데이터베이스 클러스터의 각 노드에서 중복없이 저장, 관리하도록 하며 분할 영역의 경계선 상에 위치하는 공간 데이터에 대해서만 중복 저장을 허용하여 병렬 공간 조인 연산 시 누락되는 공간 데이터가 없도록 한다. 본 기법은 공간 조인 연산 시 병렬 처리를 위한 별도의 작업 할당 과정을 거치지 않고 각 노드에서 병렬적으로 공간 조인 연산을 수행하며, 분할 경계선 상에 존재하는 공간 객체들은 여과 과정을 거쳐 한번만 공간 조인이 수행되므로 중복 결과들을 제거하기 위한 별도의 연산이 필요없는 특징을 갖는다. Ad Hoc망의 위상변화에 대한 적응성을 높일 수 있도록 한다. SQL Server 2000 그리고 LSF를 이용하였다. 그리고 구현 환경과 구성요소에 대한 수행 화면을 보였다.ool)을 사용하더라도 단순 다중 쓰레드 모델보다 더 많은 수의 클라이언트를 수용할 수 있는 장점이 있다. 이러한 결과를 바탕으로 본 연구팀에서 수행중인 MoIM-Messge서버의 네트워크 모듈로 다중 쓰레드 소켓폴링 모델을 적용하였다.n rate compared with conventional face recognition algorithms. 아니라 실내에서도 발생하고 있었다. 정량한 8개 화합물 각각과 총 휘발성 유기화합물의 스피어만 상관계수는 벤젠을 제외하고는 모두 유의하였다. 이중 톨루엔과 크실렌은 총 휘발성 유기화합물과 좋은 상관성 (톨루엔 0.76, 크실렌, 0.87)을 나타내었다. 이 연구는 톨루엔과 크실렌이 총 휘발성 유기화합물의 좋은 지표를 사용될 있고, 톨루엔, 에틸벤젠, 크실렌 등 많은 휘발성 유기화합물의 발생원은 실외뿐 아니라 실내에도 있음을 나타내고 있다.>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이