• Korean Journal of Radiology
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• 제22권5호
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• pp.770-781
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• 2021

Objective: Chemical exchange-dependent saturation transfer (CEST) MRI is sensitive for detecting solid-like proteins and may detect changes in the levels of mobile proteins and peptides in tissues. The objective of this study was to evaluate the characteristics of chemical exchange proton pools using the CEST MRI technique in patients with dementia. Materials and Methods: Our institutional review board approved this cross-sectional prospective study and informed consent was obtained from all participants. This study included 41 subjects (19 with dementia and 22 without dementia). Complete CEST data of the brain were obtained using a three-dimensional gradient and spin-echo sequence to map CEST indices, such as amide, amine, hydroxyl, and magnetization transfer ratio asymmetry (MTR_asym) values, using six-pool Lorentzian fitting. Statistical analyses of CEST indices were performed to evaluate group comparisons, their correlations with gray matter volume (GMV) and Mini-Mental State Examination (MMSE) scores, and receiver operating characteristic (ROC) curves. Results: Amine signals (0.029 for non-dementia, 0.046 for dementia, p = 0.011 at hippocampus) and MTR_asym values at 3 ppm (0.748 for non-dementia, 1.138 for dementia, p = 0.022 at hippocampus), and 3.5 ppm (0.463 for non-dementia, 0.875 for dementia, p = 0.029 at hippocampus) were significantly higher in the dementia group than in the non-dementia group. Most CEST indices were not significantly correlated with GMV; however, except amide, most indices were significantly correlated with the MMSE scores. The classification power of most CEST indices was lower than that of GMV but adding one of the CEST indices in GMV improved the classification between the subject groups. The largest improvement was seen in the MTR_asym values at 2 ppm in the anterior cingulate (area under the ROC curve = 0.981), with a sensitivity of 100 and a specificity of 90.91. Conclusion: CEST MRI potentially allows noninvasive image alterations in the Alzheimer's disease brain without injecting isotopes for monitoring different disease states and may provide a new imaging biomarker in the future.

• 한국환경복원기술학회지
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• 제27권2호
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• pp.1-16
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• 2024

To achieve carbon neutrality and restore the national environment, there is growing interest in policies to transform national land areas into green space, such as expanding nature-based solutions, increasing biodiversity, and improving ecosystem service functions. In addition to complying with international agreements such as the United Nations Framework Convention on Climate Change and the Convention on Biological Diversity, it is necessary to expand green spaces to achieve the 2050 Carbon Neutrality goal, which can be achieved by restoring the damaged land in an ecological way. However, it is challenging to implement green restoration in a systematic and active way due to conflicts of interest among landowners and lack of institutional support and advanced technology. Therefore, this study aims to develop a strategy to expand green restoration and implement it smoothly and systematically. This study examined the current status of green restoration in South Korea by investigating green restoration laws and systems and overseas trends, and by surveying the perceptions of 1,000 people selected from a pool of the public. The results of this study show that it is difficult to implement the green restoration efficiently because the laws related to restoration are scattered. According to the relevant legal plans, the perception and direction of restoration is to pursue a sustainable national land environment, allow people to benefit from nature, improve the quality of life, and nurture related industries and human resources. In the international community, it is mentioned that green restoration contributes to achieving the 2050 Carbon Neutrality goal, revitalizing green industries, developing and applying advanced technologies, maintaining consistency in restoration-related policies, expanding citizens' access to green spaces, and adopting nature-based solutions. Both experts and the public are aware of the seriousness of the damage to the natural environment and prefer restoration with human use rather than focusing on natural recovery. It is expected that this study will contribute to the future direction of green restoration and the implementation of tasks for the sustainable restoration of the national land environment and the zero-carbon era.

• Korean Journal of Radiology
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• 제25권3호
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• pp.243-256
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• 2024

Objective: We aimed to investigate whether 2-[¹⁸F]fluoro-2-deoxy-D-glucose positron emission tomography/computed tomography (2-[¹⁸F]FDG PET/CT) can aid in evaluating the risk of malignancy in ampullary tumors detected by endoscopy. Materials and Methods: This single-center retrospective cohort study analyzed 155 patients (79 male, 76 female; mean age, 65.7 ± 12.7 years) receiving 2-[¹⁸F]FDG PET/CT for endoscopy-detected ampullary tumors 5-87 days (median, 7 days) after the diagnostic endoscopy between June 2007 and December 2020. The final diagnosis was made based on histopathological findings. The PET imaging parameters were compared with clinical data and endoscopic features. A model to predict the risk of malignancy, based on PET, endoscopy, and clinical findings, was generated and validated using multivariable logistic regression analysis and an additional bootstrapping method. The final model was compared with standard endoscopy for the diagnosis of ampullary cancer using the DeLong test. Results: The mean tumor size was 17.1 ± 7.7 mm. Sixty-four (41.3%) tumors were benign, and 91 (58.7%) were malignant. Univariable analysis found that ampullary neoplasms with a blood-pool corrected peak standardized uptake value in earlyphase scan (SUVe) ≥ 1.7 were more likely to be malignant (odds ratio [OR], 16.06; 95% confidence interval [CI], 7.13-36.18; P < 0.001). Multivariable analysis identified the presence of jaundice (adjusted OR [aOR], 4.89; 95% CI, 1.80-13.33; P = 0.002), malignant traits in endoscopy (aOR, 6.80; 95% CI, 2.41-19.20; P < 0.001), SUVe ≥ 1.7 in PET (aOR, 5.43; 95% CI, 2.00-14.72; P < 0.001), and PET-detected nodal disease (aOR, 5.03; 95% CI, 1.16-21.86; P = 0.041) as independent predictors of malignancy. The model combining these four factors predicted ampullary cancers better than endoscopic diagnosis alone (area under the curve [AUC] and 95% CI: 0.925 [0.874-0.956] vs. 0.815 [0.732-0.873], P < 0.001). The model demonstrated an AUC of 0.921 (95% CI, 0.816-0.967) in candidates for endoscopic papillectomy. Conclusion: Adding 2-[¹⁸F]FDG PET/CT to endoscopy can improve the diagnosis of ampullary cancer and may help refine therapeutic decision-making, particularly when contemplating endoscopic papillectomy.

• 한국가스학회지
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• 제28권1호
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• pp.11-18
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• 2024

인화성 액체가 누출되면 풀에서 증발된 증기로 인해 근로자들에게 중독이나 질식 등의 피해를 불러올 수 있으며 화재나 폭발 등의 2차 사고로 이어질 수 있다. 이러한 피해를 예방하기 위하여 실내 작업장을 설계할 때 환기설비를 설치해야 한다. 이때, 누출된 화학물질의 특성에 따라 거동이 상이하므로 물질에 따른 적합한 환기구의 위치를 선정할 필요가 있다. 따라서 최적의 환기구 배치를 도출하기 위하여 3D CFD 시뮬레이션을 도입하였고 환기구 배치에 따른 환기효율을 정량적으로 평가하였다. 이때, 실내 작업장에서 인화성 액체가 누출되어 풀을 형성하는 상황을 가정하였고 풀에서 증발된 증기의 농도를 비교하여 최적의 환기구 배치를 도출하였다. 증기밀도가 큰 톨루엔을 대상물질로 하여 연구를 진행한 결과, 상부급기-하부배기일 때 환기효율이 가장 높아 동일한 유지비용으로 약 3.7배의 환기효과를 보이는 것을 확인하였다. 본 연구를 통해 작업장은 시뮬레이션 결과를 적용하여 환기구를 설치함으로써 근로자의 안전성을 확보할 수 있을 것으로 기대한다.

• International Journal of Stem Cells
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• 제16권4호
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• pp.425-437
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• 2023

Obesity, which continues to increase worldwide, was shown to irreversibly impair the differentiation potential and angiogenic properties of adipose tissue mesenchymal stromal cells (ADSCs). Because these cells are intended for regenerative medicine, especially for the treatment of inflammatory conditions, and the effects of obesity on the immunomodulatory properties of ADSCs are not yet clear, here we investigated how ADSCs isolated from former obese subjects (Ex-Ob) would influence macrophage differentiation and polarization, since these cells are the main instructors of inflammatory responses. Analysis of the subcutaneous adipose tissue (SAT) of overweight (OW) and Ex-Ob subjects showed the maintenance of approximately twice as many macrophages in Ex-Ob SAT, contained within the CD68⁺/FXIII-A^- inflammatory pool. Despite it, in vitro, coculture experiments revealed that Ex-Ob ADSCs instructed monocyte differentiation into a M2-like profile, and under inflammatory conditions induced by LPS treatment, inhibited HLA-DR upregulation by resting M0 macrophages, originated a similar percentage of TNF-α⁺ cells, and inhibited IL-10 secretion, similar to OW-ADSCs and BMSCs, which were used for comparison, as these are the main alternative cell types available for therapeutic purposes. Our results showed that Ex-Ob ADSCs mirrored OW-ADSCs in macrophage education, favoring the M2 immunophenotype and a mixed (M1/M2) secretory response. These results have translational potential, since they provide evidence that ADSCs from both Ex-Ob and OW subjects can be used in regenerative medicine in eligible therapies. Further in vivo studies will be fundamental to validate these observations.

• International Journal of Stem Cells
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• 제16권2호
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• pp.123-134
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• 2023

Objective: The heart contains a pool of c-kit⁺ progenitor cells which is believed to be able to regenerate. The differentiation of these progenitor cells is reliant on different physiological cues. Unraveling the underlying signals to direct differentiation of progenitor cells will be beneficial in controlling progenitor cell fate. In this regard, the role of the mitochondria in mediating cardiac progenitor cell fate remains unclear. Specifically, the association between changes in mitochondrial morphology with the differentiation status of c-kit⁺ CPCs remains elusive. In this study, we investigated the relationship between mitochondrial morphology and the differentiation status of c-kit⁺ progenitor cells. Methods and Results: c-kit⁺ CPCs were isolated from 2-month-old male wild-type FVB mice. To activate differentiation, CPCs were incubated in α-minimal essential medium containing 10 nM dexamethasone for up to 7 days. To inhibit Drp1-mediated mitochondrial fragmentation, either 10 μM or 50 μM mdivi-1 was administered once at Day 0 and again at Day 2 of differentiation. To inhibit calcineurin, either 1 μM or 5 μM ciclosporin-A (CsA) was administered once at Day 0 and again at Day 2 of differentiation. Dexamethasone-induced differentiation of c-kit⁺ progenitor cells is aligned with fragmentation of the mitochondria via a calcineurin-Drp1 pathway. Pharmacologically inhibiting mitochondrial fragmentation retains the undifferentiated state of the c-kit⁺ progenitor cells. Conclusions: The findings from this study provide an alternative view of the role of mitochondrial fusion-fission in the differentiation of cardiac progenitor cells and the potential of pharmacologically manipulating the mitochondria to direct progenitor cell fate.

• 한국토양비료학회지
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• 제7권1호
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• pp.5-16
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• 1974

경사지(傾斜地) 및 산지(山地)의 특성(特性)과 현재(現在)의 토지이용상황(土地利用狀況)을 파악(把握)하고 그 토양조건(土壤條件)에 알맞는 토지이용(土地利用) 개발(開發)을 추천(推薦)하고져 3개부락(個部落)의 농가(農家)가 다양(多樣)하게 토지(土地)를 이용(利用)하고 있는 저구릉지(低丘陵地)를 중심(中心)으로 하여 조사(調査)한 결과(結果)는 다음과 같다. 1. 잔적토(殘積土) 및 홍적토(洪積土)에 재배(栽培)되고 있는 작물(作物)은 단순(單純)하였고 그 수량(收量)은 낮았으며 따라서 이 지역(地域)의 농민(農民)들은 빈곤(貧困)하였다. 2. 토지이용율(土地利用率)은 58.4%이었으나 이 중(中) 경사지(傾斜地) 경작(耕作)에서는 토양보존(土壤保存)에 대(對)한 고려(考慮)가 없었다. 전체(全體)의 37.2%에 달(達)하는 임지(林地에)는 입목(立木)이 적었으며 토지이용(土地利用) 계획(計劃) 및 관리(管理의) 소홀(疎忽)로 점차(漸次) 황폐화(荒廢化)되여 가고 있었다. 3. 조사지역(調査地域)에서 밝혀진 토양통(土壤統)은 12개(個)이다. 잔적토(殘積土)는 적갈(赤褐)~암갈색(暗褐色)의 양질(壤質)이고, 홍적토(洪積土)는 황적(黃赤)~갈색(褐色)의 식질(埴質)이었으며, 곡간충적토(谷間沖積土)는 암갈색(暗褐色)~회색(灰色)의 양질토(壤質土)로 다양(多樣)했다. 4. 토양반응(土壤反應)은 구릉지(丘陵地)가 pH 5.0~5.2로서 홍적대지(洪積臺地) 기경지(旣耕地) pH 4.7~4.8에 비(比)하여 pH가 높은 편(便)이었으나, 유기물함량(有機物含量)은 반대(反對)로 홍적토(洪積土)가 3.3~3.6%로 구릉지(丘陵地)의 2.6~2.8% 보다 높았다. 염기치환용량(鹽基置換容量)은 8~16me/100gr이며 이는 유기물함량(有機物含量), 점토(粘土) 및 미사함량(微砂含量)과 밀접(密接)한 관계(關係)를 가지고 있다. 5. 토양(土壤)의 특성(特性)에 따라 16개(個) 토지이용적성군(土地利用適性群)으로 나눌 수 있었다. 6. 조사전(調査前) 토지이용(土地利用)과 조사후(調査後) 추천(推薦)된 토양이용(土壤利用)에는 많은 차이(差異)가 보였다. 주(主)로 임지(林地)가 초지(草地), 유실수(有實樹), 과수(果樹) 및 상전(桑田)으로 추천(推薦)되었다.

• Nuclear Medicine and Molecular Imaging
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• 제42권1호
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• pp.44-51
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• 2008

목적: 외상 후 복합부위통증증후군으로 진단된 환자에서 시행한 삼상 뼈 스캔의 판독 신뢰도를 평가하기 위하여 판독 일치도를 조사하였다. 대상 및 방법: 1994년 국제통증연구학회(IASP) 기준에 따라 외상 후 복합부위통증증후군으로 진단된 34명을 대상으로 하였다. 두 명의 핵의학 전문의가 삼상 뼈 스캔의 세부영상에서 섭취의 양상, 정도와 범위를 평가하여 관찰자내 와 관찰자간 일치도(kappa value)를 구하였다. 환측 사지 전체의 관류와 섭취가 증가되었을 때(기준 1), 지연영상에서 전체적으로 증가되었을 때(기준2), 국소이상의 섭취가 증가되었을 때(기준3)를 양성으로 판정하는 기준에 따라 재분류하여 판독자 임의로 분류하였을 때와 최종판독 일치도를 비교하였다. 결과: 세 영상에서 섭취 양상, 정도, 범위에 대한 관찰자내 일치도는 우수하였다. 세부 영상에 대한 관찰자간 일치도(0.64-0.90)에 비하여 혈액풀의 섭취 범위에 대한 일치도는 낮았다(0.55). 관찰자간 일치도는 임의의 기준으로 최종 판정하였을 때(0.63)에 비하여 공통의 양성 판정 기준에 따라 다시 분류하였을 때 약간 향상되었다(0.77-0.88). 임상시기별 임의 기준으로 분류한 관찰자간 일치도는(급성: 0.29, 만성: 0.37) 양성 판정 기준을 적용시에 크게 향상되었다(급성: 0.47-0.82, 만성: 1.0). 임상시기별 예민도는 급성에 비해 만성에서 대체적으로 낮았다. 결론: 본 연구에서 외상 후 복합부위통증증후군 환자에서 시행한 삼상 뼈 스캔의 판독 시 관찰자간 변동성이 있는 것이 검증되었다. 그 변동성은 양성 평가의 기준이 관찰자마다 다른데서 기인하였다. 외상 후 복합통증증후군 환자에서 삼상 뼈 스캔의 판독 신뢰도를 높이기 위해서는 세부 영상 및 임상시기에 따른 구체적인 양성 판정 기준을 정할 필요가 있다.

• 한국균학회소식:학술대회논문집
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• 한국균학회 2015년도 춘계학술대회 및 임시총회
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• pp.53-53
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• 2015

Agrobacterium tumefaciens-mediated transformation(ATMT) of Flammulina velutipes was used to produce a diverse number of transformants to discover the functions of gene that is vital for its variation color, spore pattern and cellulolytic activity. Futhermore, the transformant pool will be used as a good genetic resource for studying gene functions. Agrobacterium-mediated transformation was conducted in order to generate intentional mutants of F. velutipes strain KACC42777. Then Agrobacterium tumefaciens AGL-1 harboring pBGgHg was transformed into F. velutipes. This method is use to determine the functional gene of F. velutipes. Inverse PCR was used to insert T-DNA into the tagged chromosomal DNA segments and conducting sequence analysis of the F. velutipes. But this experiment had trouble in diverse morphological mutants because of dikaryotic nature of mushroom. It needed to make monokaryotic fruiting varients which introduced genes of compatible mating types. In this study, next generation sequencing data was generated from 28 strains of Flammulina velutipes with different phenotypes using Illumina Hiseq platform. Filtered short reads were initially aligned to the reference genome (KACC42780) to construct a SNP matrix. And then we built a phylogenetic tree based on the validated SNPs. The inferred tree represented that white- and brown- fruitbody forming strains were generally separated although three brown strains, 4103, 4028, and 4195, were grouped with white ones. This topological relationship was consistently reappeared even when we used randomly selected SNPs. Group I containing 4062, 4148, and 4195 strains and group II containing 4188, 4190, and 4194 strains formed early-divergent lineages with robust nodal supports, suggesting that they are independent groups from the members in main clades. To elucidate the distinction between white-fruitbody forming strains isolated from Korea and Japan, phylogenetic analysis was performed using their SNP data with group I members as outgroup. However, no significant genetic variation was noticed in this study. A total of 28 strains of Flammulina velutipes were analyzed to identify the genomic regions responsible for producing white-fruiting body. NGS data was yielded by using Illumina Hiseq platform. Short reads were filtered by quality score and read length were mapped on the reference genome (KACC42780). Between the white- and brown fruitbody forming strains. There is a high possibility that SNPs can be detected among the white strains as homozygous because white phenotype is recessive in F. velutipes. Thus, we constructed SNP matrix within 8 white strains. SNPs discovered between mono3 and mono19, the parental monokaryotic strains of 4210 strain (white), were excluded from the candidate. If the genotypes of SNPs detected between white and brown strains were identical with those in mono3 and mono19 strains, they were included in candidate as a priority. As a result, if more than 5 candidates SNPs were localized in single gene, we regarded as they are possibly related to the white color. In F. velutipes genome, chr01, chr04, chr07,chr11 regions were identified to be associated with white fruitbody forming. White and Brown Fruitbody strains can be used as an identification marker for F. veluipes. We can develop some molecular markers to identify colored strains and discriminate national white varieties against Japanese ones.

• 한국기록관리학회지
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• 제4권2호
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• pp.41-75
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• 2004

이 논문은 기록관리법의 개정과 관련하여, 우리나라 기록관리의 현황에서 개선되어야 할 방안을 크게 세 가지로 구분하여 논술하였다. 그 세 가지 사항은 바로 1)중앙기록물관리기관으로서의 <국가기록원(National Archives & Records Service of Korea)>의 위상 문제, 2)기록관리 전문인력의 제도 및 양성 문제, 3)기록박물전시관의 설치 문제이다. 연구의 결과는 다음과 같다. 첫째, 현재의 <국가기록원>은 국가 중앙기록물관리기관으로서, 행정자치부 내에서 최소한 차관급 이상의 청(廳) 단위인 <국가기록청>으로 그 위상이 반드시 승격되어야 함을 주장하였다. 둘째, 기록관리법에서 현재 '기록관리학 석사학위 이상 등'으로 규정된 학력제한 사항을 '기록관리학 학사학위 이상 등'으로 하향조정하여, 기록관리 전문인력의 저변확대를 꾀하여야 한다. 그리고 기록관리 전문인력의 공무원 채용을 위하여 '연구직종/기록관리직군'을 신설하거나, 현재의 '학예직' 및 '사서직' 및 '기록관리직'을 통합하여 새로운 '기록문화직군'을 독립직군으로 신설하는 방안도 검토되어야 함을 주장하였다. 셋째, 각 지방자치단체 기록관 사업에서는 각 지방자치단체 특유의 전통문화와 기록유산을 계승 발전시키는 것이 최우선 과제로 선정되어야 가장 중요한 사명이라 할 수 있다. 따라서 향후 개정될 기록관리법에는, 현행 기록관리법에 명시되지 못한 각 지방자치단체에 <기록관>의 설립을 의무화함과 동시에, 이 기록관 내에 이른바 <기록박물전시관>의 설치를 의무화하도록 제안하였다. 또한 해당 지방자치단체에서만 독특하게 형성된 유구한 문화와 역사를 그 지방자치단체의 기록관에서 특성화시킴으로써, 여타 지자체의 기록관과는 차별화하는 것이 매우 중요하기 때문에, 각 지자체별로 특성화된 기록관의 명칭을 부여하는 방안도 아울러 제시하였다.