Brain Topological Correlates of Motor Performance Changes After Repetitive Transcranial Magnetic Stimulation

Park, Chang-hyun,Chang, Won Hyuk,Yoo, Woo-Kyoung,Shin, Yong-Il,Kim, Sung Tae,Kim, Yun-Hee Mary Ann Liebert 2014 Brain connectivity Vol.4 No.4

<P>Repetitive transcranial magnetic stimulation (rTMS) influences the brain temporally beyond the stimulation period and spatially beyond the stimulation site. Application of rTMS over the primary motor cortex (M1) has been shown to lead to plastic changes in interregional connectivity over the motor system as well as alterations in motor performance. With a sequential combination of rTMS over the M1 and functional magnetic resonance imaging (fMRI), we sought changes in the topology of brain networks and specifically the association of brain topological changes with motor performance changes. In a sham-controlled parallel group experimental design, real or sham rTMS was administered to each of the 15 healthy subjects without prior motor-related dysfunctions, over the right M1 at a high frequency of 10 Hz. Before and after the intervention, fMRI data were acquired during a sequential finger motor task using the left, nondominant hand. Changes in the topology of brain networks were assessed in terms of global and local efficiency, which measures the efficiency in transporting information at global and local scales, respectively, provided by graph-theoretical analysis. Greater motor performance changes toward improvements after real rTMS were shown in individuals who exhibited more increases in global efficiency and more decreases in local efficiency. The enhancement of motor performance after rTMS is supposed to be associated with brain topological changes, such that global information exchange is facilitated, while local information exchange is restricted.</P>

Safety and efficacy of dietary supplement (gintonin-enriched fraction from ginseng) in subjective memory impairment: A randomized placebo-controlled trial

Lee Woo-Jin,Shin Yong-Won,Chang Hyeyeon,Shin Hye-Rim,Kim Won-Woo,Jung Seok-Won,Kim Manho,Nah Seung-Yeol 한국한의학연구원 2022 Integrative Medicine Research Vol.11 No.1

Background: Gintonin inhibits β-amyloid production, increases acetylcholine level in the brain, and promotes neurogenesis. We evaluated the efficacy of gintonin-enriched fraction (GEF) in improving the cognitive performance in subjective memory impairment. Methods: In this 8-week, randomized, assessor and participant blinded, placebo–controlled study, participants with subjective memory impairment but preserved cognitive function (Korean Mini-Mental State Examination [K-MMSE] score ≥23) were assigned to GEF 300mg/day or placebo. K-MMSE, Korean versions of the Alzheimer's disease assessment scale, color-word stroop test (K-CWST), clinical dementia rating, and Beck depression inventory-II were evaluated along with the safety profiles. The primary outcome was set as the change in the K-MMSE. Results: Seventy-six participants complete the study protocol. After 8 weeks, there was no inter-group difference in the primary or secondary outcome score changes. However, GEF group showed an improvement in the K-MMSE scores (P= 0.026), and in the number of correct answers in both word reading (P= 0.008) and color reading (P= 0.005) of K-CWST, although only the improvement in the K-CWST scores were higher than the minimum clinically important difference. The frequency of adverse events was comparable between the groups and all were of mild severity. Conclusion: GEF is safe but might not be effective in treating subjective memory impairment within the current study setting. However, GEF showed a trend of improving the global cognition and the frontal executive function. Further large-sized studies with longer follow-up period are warranted. Clinical trial registration: This clinical trial was registered at Clinical Research Information Service of Korea Centers for Disease Control and Prevention: KCT0004636. Background: Gintonin inhibits β-amyloid production, increases acetylcholine level in the brain, and promotes neurogenesis. We evaluated the efficacy of gintonin-enriched fraction (GEF) in improving the cognitive performance in subjective memory impairment. Methods: In this 8-week, randomized, assessor and participant blinded, placebo–controlled study, participants with subjective memory impairment but preserved cognitive function (Korean Mini-Mental State Examination [K-MMSE] score ≥23) were assigned to GEF 300mg/day or placebo. K-MMSE, Korean versions of the Alzheimer's disease assessment scale, color-word stroop test (K-CWST), clinical dementia rating, and Beck depression inventory-II were evaluated along with the safety profiles. The primary outcome was set as the change in the K-MMSE. Results: Seventy-six participants complete the study protocol. After 8 weeks, there was no inter-group difference in the primary or secondary outcome score changes. However, GEF group showed an improvement in the K-MMSE scores (P= 0.026), and in the number of correct answers in both word reading (P= 0.008) and color reading (P= 0.005) of K-CWST, although only the improvement in the K-CWST scores were higher than the minimum clinically important difference. The frequency of adverse events was comparable between the groups and all were of mild severity. Conclusion: GEF is safe but might not be effective in treating subjective memory impairment within the current study setting. However, GEF showed a trend of improving the global cognition and the frontal executive function. Further large-sized studies with longer follow-up period are warranted. Clinical trial registration: This clinical trial was registered at Clinical Research Information Service of Korea Centers for Disease Control and Prevention: KCT0004636.

Evaluation of a Dual-Cooled Annular Fuel Heat Split and Temperature Distribution

YANG, Yong Sik,SHIN, Chang Hwan,CHUN, Tae Hyun,SONG, Kun Woo Atomic Energy Society of Japan 2009 Journal of nuclear science and technology Vol.46 No.8

<P>The heat flux and fuel temperature of an annular fuel rod was analyzed using a newly developed program, DUO_THERM. The dual-cooled annular fuel rod has both inner and outer coolant channels. The heat fluxes to inner and outer claddings can change during irradiation because of the variation in the gap conductances of the inner and outer sides. The heat flux is a very important design factor affecting fuel integrity and safety. However, in an annular fuel design, the prediction of heat flux is very complicated because it is closely connected with size changes of two gaps, which are different from each other during irradiation. A burnup increase and power change can cause pellet and cladding radial deformation and eventually change the gap width. Because an annular fuel has two gaps at both sides and their heat resistances are very large, an imbalance of the gap width can lead to heat flux asymmetry. Therefore, a pellet and cladding dimensional change including densification, swelling, creep, and thermal expansion must be considered in the calculation of heat flux and temperature. By using the DUO_THERM program, the changes in heat flux and temperature during an operation were evaluated with respect to a reference design of an annular fuel. The results of the evaluation showed that the heat flux of an annular fuel was greatly affected by the inner and outer gap conductance changes. The heat flux of the inner cladding was maximum at zero burnup, but that of the outer cladding was maximum at the burnup of the outer gap closing. In addition, the maximum fuel temperature location was changed by gap conductance asymmetry.</P>

PET/CT 검사 환자의 피폭선량 경감을 위한 연구

김봉수,표성재,조용귀,신채호,조진우,김창호,Kim, Bong-Su,Pyo, Sung-Jai,Cho, Yong-Gyi,Shin, Chai-Ho,Cho, Jin-Woo,Kim, Chang-Ho 대한핵의학기술학회 2009 핵의학 기술 Vol.13 No.3

목적 : 환자의 피폭선량 감소를 위해 PET/CT검사 시Pitch를 조절하여 환자의 피폭선량을 줄일 수 있는 방법에 대해 고려해 보고 Pitch 조정이 CT 영상과 PET의 SUV값에 영향을 주어 변화가 있는지를 살펴 보고자 한다. 방법 : Siemens사의 Biograph Positron Emission Tomography (PET) Scanner (CT 형식 : TRCT-240-130 (WCT-240-130)을 사용하였다. 환자의 피폭선량 평가로는 CT 조사선량 측정기인 PTW-DIADOS 11003/1383를 사용하여 선량을 측정하였고 Pitch 조정이 CT 영상에 미치는 영향을 알아보기 위해 AAPM Standard Phantom을 이용하여 pitch 변화에 따른 CT 영상의 공간 분해능을 측정하여 비교하였다. 그리고, PET source consists of a solid radioactive cylinder phantom을 사용하여 Pitch 변화에 따른 Fusion 영상의 SUV값을 산출하여 PET/CT 영상에서 SUV값이 변하였는지 확인하였다. 결과 : 2slice CT scanner에서는 Pitch가 0.7~1.3까지는 방사선량이 크게 떨어지나 1.5~1.9까지는 방사선량의 감소가 작아졌으며 Pitch값이 커질수록 환자의 피폭선량이 작아지는 것을 알 수 있었다. 그리고 Pitch값의 증가에 따른 SUV값의 변화는 거의 없었으며. Pitch값이 PET SUV값에 영향을 주지 않는다는 것을 알 수 있었다. Pitch의 변화가 CT 영상에도 크게 영향을 주지 않는 것을 알 수 있었다. 결론 : 위의 결과로 PET/CT를 사용하는 병원은 영상의 왜곡이 없고 PET SUV값에 영향을 주지 않는 범위 내에서 각 병원에 맞는 Pitch값을 찾아서 환자의 피폭 경감을 위해 노력해야 할 것이다. 그리고 Multi-detector를 가진 CT scanner인 경우에 모두 해당 될 것이라 생각되며 향후 다른 장비에서도 이와 같은 실험이 필요하다 하겠다. Purpose: As the number of patients has increased since the installation of a PET/CT, we are now examining about 2500-3000 annually. We have realized that if we properly adjust a pitch under the same condition of a CT during a PET/CT exam, radiation quantity that reaches the patient can change. In order to reduce the exposure dose of a patient, the research examines a method of reducing the exposure dose of a patient by controlling the pitch during a PET/CT exam, viewing whether the adjustment of the pitch influences CT image and PET SUV. Methods: The equipment used is a Biograph Positron Emission Tomography (PET) Scanner (CT type: TRCT-240-130 (WCT-240-130)) of Siemens company. For the evaluation of exposure dose of a patient, we measured radiation quantities using a PTW-DIADOS 11003/1383, which is a CT radiation measurement instrument used by Siemens. We measured and analyzed the space resolutions of CT images caused by the change of pitches using an AAPM Standard Phantom in order to see how the adjustment of pitches influenced the CT images. In addition, in order to obtain SUVs caused by each change of pitches using a PET source made with a solid radioactive cylinder phantom, we confirmed whether the SUVs changed in the PET/CT images by calculating the SUVs of the fusion images caused by the change of pitches after obtaining CT and PET images and finishing the test. Results: 2slice CT scanner showed that radiation quantities largely dropped when pitches ranged from 0.7 to 1.3 and that the reduction of radiation quantities were smaller when pitches ranged from 1.5 to 1.9. That is, we found that the bigger pitch values are the smaller the radiation quantities of a patient are. Moreover, we realized that there is no change of SUVs caused by the increase of pitches and that pitch values do not influence PET SUVs and the quality of CT images. It is judged that using 1.5 as a pitch value contributes to the reduction of exposure dose of a patient as long as there is no problem in the quality of an image. Conclusions: When seeing the result of the research, hospital using a PET/CT should make an effort to reduce the exposure dose of a patient seeking pitch values appropriate for their hospital within the range in which there is no image distortion and PET SUVs are not influenced from pitches. We think that the research can apply to all multi-detectors having a CT scanner and that such a research will be needed for other equipments in the future.

Safety of a Traditional Korean Medicine, Cheonggan extracts (CGX): A 2-week Single-dose Toxicity Study in SD Rats and Beagle Dogs

Shin, Jang-Woo,Cho, Jung-Hyo,Seo, Dong-Seok,Sung, Nak-Won,Kwon, Min,Son, Chang-Gue The Society of Korean Medicine 2009 대한한의학회지 Vol.30 No.6

Objectives: To evaluate the acute toxic effects and approximate lethal dose of Cheonggan extracts (CGX) in SD rats and beagle dogs. Methods: Male and female rats were divided into 4 groups (Control, CGX 1250, CGX 2500, CGX 5000) respectively and male and female dogs were divided into two groups respectively (Control, CGX 5000) respectively. A single oral dose of CGX was treated to the rats and dogs. Mortality, signs of gross toxicity, and behavioral changes were observed over 14 days. All animals were observed every hour for 4 hours after administration and once a day thereafter for 14 days. Body weights were determined at $0_{th}$, $7_{th}$, and $14_{th}$ days. All surviving animals were sacrificed and necrotized. Major organs were inspected visually for gross findings. Results: No animals died in any of the groups during the experimental period (2 weeks), rats or dogs. Body weights of rats and dogs during the experiment continuously increased in all groups but there was no significant change. No abnormal clinical signs were observed for 2 weeks after a single administration of CGX in any dose group of CGX, rats or dogs. No abnormal findings in major organs were observed in any group of rats or dogs. Conclusion: CGX does not have acute toxic effects in rats or dogs. Therefore, an approximate lethal dose is assumed to exceed 5000 mg/kg in both rats and dogs.

Aptamer‑linked immobilized sorbent assay for detecting GMO marker, phosphinothricin acetyltransferase (PAT)

Woo‑Ri Shin,Mun‑Jong Lee,SEKHONSIMRANJEET SINGH,Ji Hun Kim,Sun Chang Kim,Byung‑Kwan Cho,Ji‑Young Ahn,Yang‑Hoon Kim 대한독성 유전단백체 학회 2020 Molecular & cellular toxicology Vol.16 No.3

Background Development of genetically modified crops has rapidly increased in last few years. The most widely grown GM crops express genes that confer herbicide tolerance and insect resistance. Detection system of GM crops is important for safety evaluation before its consumption. Objective The purpose of this research is to detect GM crops, especially PAT, in food-samples. Results The bar gene (PAT protein, herbicide resistant) was cloned in pGEX-4T-1 and expressed by E. coli. The high-affinity PAT-specific single-stranded DNA (ssDNA) aptamers were obtained from a random DNA library. MOE docking study was performed to identify the potential binding region of the selected aptamers on PAT. Aptamer-linked immobilized sorbent assay (ALISA) method was used to detect PAT. Conclusion We screened aptamer against PAT for developing an efficient detection method. The selected PAT specific aptamers, HRPA-05 and HRPA-07, showed the distinct target binding behaviors, and detected PAT protein by aptamer-linked immobilized sorbent assay method with high efficiency and selectivity.

Fault Diagnosis of Roll Shape Under the Speed Variation in Hot Rolling Mill

Chang Woo Lee,Hyun Kyoo Kang,Kee Hyun Shin 대한기계학회 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.9

The metal processing system usually consists of various components such like motors, work rolls, backup rolls, idle rolls, sensors, etc. Even a simple fault in a single component in the system may cause a serious damage on the final product. It is therefore necessary to diagnose the faults of the components to detect and prevent system failure. Especially, the defects in a work roll are critical to the quality of strip. It is especially difficult to detect faults of a roll by using the existing frequency analysis method if the speed of the roll is changing. In this study, a new diagnosis method for roll eccentricity under the roll speed changes was developed. The new method was induced from analyzing the rolling mechanism by using rolling force models, radius -speed relationship, and measured rolling force, etc. Simulation results by using the field data show that the proposed method is very useful.

Safety of a Traditional Korean Medicine, Cheonggan extracts (CGX)

Jang-Woo Shin,Jung-Hyo Cho,Dong-Seok Seo,Nak-Won Sung,Min Kwon,Chang-Gue Son 대한한의학회 2009 대한한의학회지 Vol.30 No.6

Surface albedo from the geostationary Communication, Ocean and Meteorological Satellite (COMS)/Meteorological Imager (MI) observation system

Lee, Chang Suk,Han, Kyung-Soo,Yeom, Jong-Min,Lee, Kyeong-sang,Seo, Minji,Hong, Jinkyu,Hong, Je-Woo,Lee, Keunmin,Shin, Jinho,Shin, In-Chul,Chun, Junghwa,Roujean, Jean-Louis Informa UK (TaylorFrancis) 2018 GISCIENCE AND REMOTE SENSING Vol.55 No.1

<P>The surface albedo is an essential climate variable that is considered in many applications used for predicting climate and understanding the mechanisms of climate change. In this study, surface albedo was estimated using a bidirectional reflectance distribution function model based on Communication, Ocean and Meteorological Satellite/Meteorological Imager data. Geostationary orbiting satellite data are suitable for a level 2 product like albedo, which requires a synthetic process to estimate. The authors modified established methods to consider the geometry of the solar-surface-sensor of COMS/MI. Of note, the viewing zenith angle term was removed from the kernel integration used for estimating spectral albedo. Finally, the spectral (narrow) albedo was converted into the broadband albedo with shortwave length (approximately 0.3-2.5 m). This study determined conversion coefficients using only one spectral albedo of visible channel. The estimated albedo had a relatively high correlation with Satellite Pour l'Observation de la Terre/Vegetation and low unweighted error values specific for land types or times. The validation results show that estimated albedo has a root mean square error of 0.0134 at Jeju flux site that indicates accuracy similar to that of other satellite-based products.</P>

Fault Diagnosis of Roll Shape Under the Speed Variation in Hot Rolling Mill

Lee, Chang-Woo,Kang, Hyun-Kyoo,Shin, Kee-Hyun The Korean Society of Mechanical Engineers 2006 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.20 No.9

The metal processing system usually consists of various components such like motors, work rolls, backup rolls, idle rolls, sensors, etc. Even a simple fault in a single component in the system may cause a serious damage on the final product. It is therefore necessary to diagnose the faults of the components to detect and prevent system failure. Especially, the defects in a work roll are critical to the quality of strip. It is especially difficult to detect faults of a roll by using the existing frequency analysis method if the speed of the roll is changing. In this study, a new diagnosis method for roll eccentricity under the roll speed changes was developed. The new method was induced from analyzing the rolling mechanism by using rolling force models, radius-speed relationship, and measured rolling force, etc. Simulation results by using the field data show that the proposed method is very useful.