• 생명과학회지
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• 제17권12호
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• pp.1627-1633
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• 2007

c-Jun N-terminal kinase (JNK)-interacting protein 1(JIP1)은 비계단백질(scaffold protein)로서 신경 세포와 ??장${\beta}$세포에서 많이 발현된다. 본 연구에서는 배양한 흰쥐 해마신경세포에서 JIP1, JIP-2 및 JIP-3을 모두 인식하는 항체를 이용하여 이들의 세포내 표현을 조사하였다. 전반적으로 JIP은 세포체와 가지돌기에 반점 모양으로 표현되었다. 이 JIP 반점들을 통계적으로 분석한 결과 흥분성 연접후표지인 PSD95 및 ${\alpha}CaMKII$ 반점 과 각각 $54.8{\pm}4.0%$ 및 $94.1{\pm}4.5%$가 겹쳐졌다. 반면에 억제성 연접후표지인 그리신수용체 및 gephyrin 반점과는 각각 단지 $8.6{\pm}0.5%$ 및 $7.3{\pm}0.5%$만 겹쳐졌다. 한편 lipid raft의 표지인 flotillin 반점의 상당부분$(29.3{\pm}1.0%)$이 JIP 반점과 겹쳐졌다. 또한, JIP은 일부 가지돌기의 끝부분에 매우 강하게 발편되었으며 축삭에는 표현이 미미하였다. 이 결과들은 JIP 단백질이 흥분성 연접후구역, 일부 lipid raft, 그리고 일부 가지돌기 끝부분에 주로 위치함을 의미한다.

• 한국지반환경공학회 논문집
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• 제17권5호
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• pp.27-36
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• 2016

저영향개발(LID) 기법은 물순환을 고려한 친환경 도시계획기법으로 개발 이전의 물수지를 회복시키려는 빗물관리 방법이다. 본 연구에서는 도시지역에 적용 가능한 LID 기법 중 4개(침투도랑, 식생수로, 도심형 인공습지, 측구형 침투도랑)를 선정하여 실제 적용될 지역에 시범 단지를 조성하였으며, 실제 강우와 인공강우를 이용한 모니터링을 통해 각 시설의 물순환 및 수질개선 효과를 평가하였다. 다양한 강우사상에서 모니터링한 결과 LID 시설의 표면적과 유역면적비, 그리고 시설용량과 유역면적비가 클수록 모든 강우사상에서 유출이 발생하지 않았다. 또한, 식생수로와 침투도랑은 모든 강우(최대 17.2mm)에서 유출이 발생하지 않았으며, 도심형 인공습지와 측구형 침투도랑에서는 유출이 발생하였는데 도심형 인공습지는 10mm 이하의 강우에서 유출 저감율이 높았으며, 측구형 침투도랑은 10mm 이하 및 이상의 강우에서 유사하게 나타났다. LID 시설의 구조와 강우사상, 선행건기일수에 따라 차이가 있으나 LID의 적용으로 물수지 개선 및 비점오염원 물질의 저감이 가능하다.

• 방사선산업학회지
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• 제9권1호
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• pp.47-55
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• 2015

Research and investigation is required for the exposure dose of radiation workers to work in the dental hospital as increasing interest in exposure dose of the dental hospital recently accordingly, study aim to minimize radiation exposure by making a follow-up study of individual exposure doses of radiation workers, analyzing the status on individual radiation exposure management, prediction the radiation disability risk levels by radiation, and alerting the workers to the danger of radiation exposure. Especially given the changes in the dental hospital radiation safety awareness conducted the study in order to minimize radiation exposure. This study performed analyses by a comparison between general and dental hospital, comparing each occupation, with the 116,220 exposure dose data by quarter and year of 5,811 subjects at general and dental hospital across South Korea from January 1, 2008 through December 31, 2012. The following are the results obtained by analyzing average values year and quarter. In term of hospital, average doses were significantly higer in general hospitals than detal ones. In terms of job, average doses were higher in radiological technologists the other workes. Especially, they showed statistically significant differences between radiological technologists than dentists. The above-mentioned results indicate that radiation workers were exposed to radiation for the past 5 years to the extent not exceeding the dose limit (maximum $50mSv\;y^{-1}$). The limitation of this study is that radiation workers before 2008 were excluded from the study. Objective evaluation standards did not apply to the work circumstance or condition of each hospital. Therefore, it is deemed necessary to work out analysis criteria that will be used as objective evaluation standard. It will be necessary to study radiation exposure in more precise ways on the basis of objective analysis standard in the furture. Should try to minimize the radiation individual dose of radiation workers.

• Animal Bioscience
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• 제34권10호
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• pp.1590-1599
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• 2021

Objective: This study investigates the expression patterns of toll-like receptors (TLRs) and intracellular mediators in horse muscle cells after exercise, and the relationship between TLRS expression in stressed horse muscle cells and immune cell migration toward them. Methods: The expression patterns of the TLRs (TLR2, TLR4, and TLR8) and downstream signaling pathway-related genes (myeloid differentiation primary response 88 [MYD88]; activating transcription factor 3 [ATF3]) are examined in horse tissues, and horse peripheral blood mononuclear cells (PBMCs), polymorphonuclear cells (PMNs) and muscles in response to exercise, using the quantitative reverse transcription-polymerase chain reaction (qPCR). Expressions of chemokine receptor genes, i.e., C-X-C motif chemokine receptor 2 (CXCR2) and C-C motif chemokine receptor 5 (CCR5), are studied in PBMCs and PMNs. A horse muscle cell line is developed by transfecting SV-T antigen into fetal muscle cells, followed by examination of muscle-specific genes. Horse muscle cells are treated with stressors, i.e., cortisol, hydrogen peroxide (H₂O₂), and heat, to mimic stress conditions in vitro, and the expression of TLR4 and TLR8 are examined in stressed muscle cells, in addition to migration activity of PBMCs toward stressed muscle cells. Results: The qPCR revealed that TLR4 message was expressed in cerebrum, cerebellum, thymus, lung, liver, kidney, and muscle, whereas TLR8 expressed in thymus, lung, and kidney, while TLR2 expressed in thymus, lung, and kidney. Expressions of TLRs, i.e., TLR4 and TLR8, and mediators, i.e., MYD88 and ATF3, were upregulated in muscle, PBMCs and PMNs in response to exercise. Expressions of CXCR2 and CCR5 were also upregulated in PBMCs and PMNs after exercise. In the muscle cell line, TLR4 and TLR8 expressions were upregulated when cells were treated with stressors such as cortisol, H₂O₂, and heat. Migration of PBMCs toward stressed muscle cells was increased by exercise and oxidative stresses, and combinations of these. Treatment with methylsulfonylmethane (MSM), an antioxidant on stressed muscle cells, reduced migration of PBMCs toward stressed muscle cells. Conclusion: In this study, we have successfully cultured horse skeletal muscle cells, isolated horse PBMCs, and established an in vitro system for studying stress-related gene expressions and function. Expression of TLR4, TLR8, CXCR2, and CCR5 in horse muscle cells was higher in response to stressors such as cortisol, H₂O₂, and heat, or combinations of these. In addition, migration of PBMCs toward muscle cells was increased when muscle cells were under stress, but inhibition of reactive oxygen species by MSM modulated migratory activity of PBMCs to stressed muscle cells. Further study is necessary to investigate the biological function(s) of the TLR gene family in horse muscle cells.

• Korean Journal of Radiology
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• 제19권6호
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• pp.1119-1129
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• 2018

Objective: To compare the image quality of low-tube-voltage and low-iodine-concentration-contrast-medium (LVLC) computed tomography urography (CTU) with iterative reconstruction (IR) with that of conventional CTU. Materials and Methods: This prospective, multi-institutional, randomized controlled trial was performed at 16 hospitals using CT scanners from various vendors. Patients were randomly assigned to the following groups: 1) the LVLC-CTU (80 kVp and 240 mgI/mL) with IR group and 2) the conventional CTU (120 kVp and 350 mgI/mL) with filtered-back projection group. The overall diagnostic acceptability, sharpness, and noise were assessed. Additionally, the mean attenuation, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure of merit (FOM) in the urinary tract were evaluated. Results: The study included 299 patients (LVLC-CTU group: 150 patients; conventional CTU group: 149 patients). The LVLC-CTU group had a significantly lower effective radiation dose ($5.73{\pm}4.04$ vs. $8.43{\pm}4.38mSv$) compared to the conventional CTU group. LVLC-CTU showed at least standard diagnostic acceptability (score ${\geq}3$), but it was non-inferior when compared to conventional CTU. The mean attenuation value, mean SNR, CNR, and FOM in all pre-defined segments of the urinary tract were significantly higher in the LVLC-CTU group than in the conventional CTU group. Conclusion: The diagnostic acceptability and quantitative image quality of LVLC-CTU with IR are not inferior to those of conventional CTU. Additionally, LVLC-CTU with IR is beneficial because both radiation exposure and total iodine load are reduced.

• Journal of Ecology and Environment
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• 제45권3호
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• pp.143-151
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• 2021

Background: Plants are able to optimize defense responses induced by various herbivores, which have different feeding strategies. Local and systemic responses within a plant after herbivory are essential to modulate herbivore-specific plant responses. For instance, leaf-chewing herbivores elicit jasmonic acid signaling, which result in the inductions of toxic chemicals in the attacked leaf (tissue-specific responses) and also in the other unattacked parts of the plant (systemic responses). Root herbivory induces toxic metabolites in the attacked root and alters the levels of transcripts and metabolites in the unattacked shoot. However, we have little knowledge of the local and systemic responses against stem-boring herbivores. In this study, we examined the systemic changes in metabolites in the wild tobacco Nicotiana attenuata, when the stem-boring herbivore Trichobaris mucorea attacks. Results: To investigate the systemic responses of T. mucorea attacks, we measured the levels of jasmonic acid (JA), JA-dependent secondary metabolites, soluble sugars, and free amino acids in 7 distinct tissues of N. attenuata: leaf lamina with epidermis (LLE), leaf midrib (LM), stem epidermis (SE), stem pith (SP), stem vascular bundle (SV), root cortex with epidermis (RCE), and root vascular bundle (RV). The levels of JA were increased in all root tissues and in LM by T. mucorea attacks. The levels of chlorogenic acids (CGAs) and nicotine were increased in all stem tissues by T. mucorea. However, CGA was systematically induced in LM, and nicotine was systematically induced in LM and RCE. We further tested the resource allocation by measuring soluble sugars and free amino acids in plant tissues. T. mucorea attacks increased the level of free amino acids in all tissues except in LLE. The levels of soluble sugars were significantly decreased in SE and SP, but increased in RV. Conclusions: The results reveal that plants have local- and systemic-specific responses in response to attack from a stem-boring herbivore. Interestingly, the level of induced secondary metabolites was not consistent with the systemic inductions of JA. Spatiotemporal resolution of plant defense responses against stem herbivory will be required to understand how a plant copes with attack from herbivores from different feeding guilds.

• Journal of Radiation Protection and Research
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• 제46권1호
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• pp.14-23
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• 2021

Background: For radiological protection and control, the International Commission on Radiological Protection (ICRP) provides the nominal risk coefficients related to radiation exposure, which can be extrapolated using the excess relative risk and excess absolute risk obtained from the Life Span Study of atomic bomb survivors in Hiroshima and Nagasaki with the dose and dose-rate effectiveness factor (DDREF). Materials and Methods: Since it is impossible to directly estimate the radiation risk at doses less than approximately 100 mSv only from epidemiological knowledge and data, support from radiation biology is absolutely imperative, and thus, several national and international bodies have advocated the importance of bridging knowledge between biology and epidemiology. Because of the accident at the Tokyo Electric Power Company (TEPCO)'s Fukushima Daiichi Nuclear Power Station in 2011, the exposure of the public to radiation has become a major concern and it was considered that the estimation of radiation risk should be more realistic to cope with the prevailing radiation exposure situation. Results and Discussion: To discuss the issues from wide aspects related to radiological protection, and to realize bridging knowledge between biology and epidemiology, we have established a research group to develop low-dose and low-dose-rate radiation risk estimation methodology, with the permission of the Japan Health Physics Society. Conclusion: The aim of the research group was to clarify the current situation and issues related to the risk estimation of low-dose and low-dose-rate radiation exposure from the viewpoints of different research fields, such as epidemiology, biology, modeling, and dosimetry, to identify a future strategy and roadmap to elucidate a more realistic estimation of risk against low-dose and low-dose-rate radiation exposure.

• 대한토목학회논문집
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• 제26권3B호
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• pp.279-289
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• 2006

최근에 수문시계열로부터 저차원의 비선형 거동을 재구성하고자 하는 연구가 활발히 진행되고 있다. 이러한 관점에서 본 연구에서는 Support Vector Machine(SVM)을 이용하여 우수한 상태-공간 재구성 능력을 갖는 비선형 예측모형을 구성하여 Great Salt Lake(GSL) Volume에 적용하였다. SVM은 Kernel 함수로부터 유도된 고차원의 특성공간 안에서 선형함수의 가상공간을 이용하는 Machine Learning 방법론이다. 또한 SVM은 훈련자료로부터 얻어지는 평균제곱오차가 아닌 일반화된 오차를 최소화함으로써 상대적으로 기존 방법에 비해 적은 수의 매개변수와 과적합(over fitting)을 피하면서 비선형 함수의 최적화가 가능하다. 본 연구에서 제시한 SVM 회귀분석의 적용성은 미국의 GSL의 2주 간격 Volume을 대상으로 검토하였다. SVM을 이용한 비선형 예측모형은 GSL Volume의 2주(1-Step), 8주(4-Step)와 반복예측(Iterated Prediction, 121-Step)까지 적용되었다. 본 연구에서는 극치사상 즉, 급격한 감소 및 증가 구간을 예측하는데 있어서 훈련구간과 예측구간을 구분하여 모형의 신뢰성을 평가하였다. 예측결과SVM은 훈련자료로부터 적은 수의 관측치를 이용하여 동역학적 거동을 추출할 수 있었으며 실제 관측자료와 거의 유사한 예측이 가능함을 통계적 지표로 확인할 수 있었다. 따라서 비선형 수문시계열의 단기 예측을 위한 모형으로 적용이 가능할 것으로 판단된다.

• Korean Journal of Radiology
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• 제22권11호
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• pp.1777-1785
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• 2021

Objective: To investigate the accuracy of the Agatston score obtained with the ultra-high-pitch (UHP) acquisition mode using tin-filter spectral shaping (Sn150 kVp) and a kVp-independent reconstruction algorithm to reduce the radiation dose. Materials and Methods: This prospective study included 114 patients (mean ± standard deviation, 60.3 ± 9.8 years; 74 male) who underwent a standard 120 kVp scan and an additional UHP Sn150 kVp scan for coronary artery calcification scoring (CACS). These two datasets were reconstructed using a standard reconstruction algorithm (120 kVp + Qr36d, protocol A; Sn150 kVp + Qr36d, protocol B). In addition, the Sn150 kVp dataset was reconstructed using a kVp-independent reconstruction algorithm (Sn150 kVp + Sa36d, protocol C). The Agatston scores for protocols A and B, as well as protocols A and C, were compared. The agreement between the scores was assessed using the intraclass correlation coefficient (ICC) and the Bland-Altman plot. The radiation doses for the 120 kVp and UHP Sn150 kVp acquisition modes were also compared. Results: No significant difference was observed in the Agatston score for protocols A (median, 63.05; interquartile range [IQR], 0-232.28) and C (median, 60.25; IQR, 0-195.20) (p = 0.060). The mean difference in the Agatston score for protocols A and C was relatively small (-7.82) and with the limits of agreement from -65.20 to 49.56 (ICC = 0.997). The Agatston score for protocol B (median, 34.85; IQR, 0-120.73) was significantly underestimated compared with that for protocol A (p < 0.001). The UHP Sn150 kVp mode facilitated an effective radiation dose reduction by approximately 30% (0.58 vs. 0.82 mSv, p < 0.001) from that associated with the standard 120 kVp mode. Conclusion: The Agatston scores for CACS with the UHP Sn150 kVp mode with a kVp-independent reconstruction algorithm and the standard 120 kVp demonstrated excellent agreement with a small mean difference and narrow agreement limits. The UHP Sn150 kVp mode allowed a significant reduction in the radiation dose.

• Korean Journal of Radiology
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• 제22권6호
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• pp.983-993
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• 2021

Objective: To investigate the image quality of ultralow-dose CT (ULDCT) of the chest reconstructed using a cycle-consistent generative adversarial network (CycleGAN)-based deep learning method in the evaluation of pulmonary tuberculosis. Materials and Methods: Between June 2019 and November 2019, 103 patients (mean age, 40.8 ± 13.6 years; 61 men and 42 women) with pulmonary tuberculosis were prospectively enrolled to undergo standard-dose CT (120 kVp with automated exposure control), followed immediately by ULDCT (80 kVp and 10 mAs). The images of the two successive scans were used to train the CycleGAN framework for image-to-image translation. The denoising efficacy of the CycleGAN algorithm was compared with that of hybrid and model-based iterative reconstruction. Repeated-measures analysis of variance and Wilcoxon signed-rank test were performed to compare the objective measurements and the subjective image quality scores, respectively. Results: With the optimized CycleGAN denoising model, using the ULDCT images as input, the peak signal-to-noise ratio and structural similarity index improved by 2.0 dB and 0.21, respectively. The CycleGAN-generated denoised ULDCT images typically provided satisfactory image quality for optimal visibility of anatomic structures and pathological findings, with a lower level of image noise (mean ± standard deviation [SD], 19.5 ± 3.0 Hounsfield unit [HU]) than that of the hybrid (66.3 ± 10.5 HU, p < 0.001) and a similar noise level to model-based iterative reconstruction (19.6 ± 2.6 HU, p > 0.908). The CycleGAN-generated images showed the highest contrast-to-noise ratios for the pulmonary lesions, followed by the model-based and hybrid iterative reconstruction. The mean effective radiation dose of ULDCT was 0.12 mSv with a mean 93.9% reduction compared to standard-dose CT. Conclusion: The optimized CycleGAN technique may allow the synthesis of diagnostically acceptable images from ULDCT of the chest for the evaluation of pulmonary tuberculosis.