• Investigative Magnetic Resonance Imaging
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• v.25 no.1
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• pp.23-34
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• 2021

Purpose: Differentiating between glioblastoma and solitary metastasis is very important for the planning of further workup and treatment. We assessed the ability of various morphological parameters using conventional MRI and diffusion-based techniques to distinguish between glioblastomas and solitary metastases in tumoral and peritumoral regions. Materials and Methods: We included 38 patients with solitary brain tumors (21 glioblastomas, 17 solitary metastases). To find out if there were differences in the morphologic parameters of enhancing tumors, we analyzed their shape, margins, and enhancement patterns on postcontrast T1-weighted images. During analyses of peritumoral regions, we assessed the extent of peritumoral non-enhancing lesion on T2- and postcontrast T1-weighted images. We also aimed to detect peritumoral neoplastic cell infiltration by visual assessment of T2-weighted and diffusion-based images, including DWI, ADC maps, and exponential DWI, and evaluated which sequence depicted peritumoral neoplastic cell infiltration most clearly. Results: The shapes, margins, and enhancement patterns of tumors all significantly differentiated glioblastomas from metastases. Glioblastomas had an irregular shape, ill-defined margins, and a heterogeneous enhancement pattern; on the other hand, metastases had an ovoid or round shape, well-defined margins, and homogeneous enhancement. Metastases had significantly more extensive peritumoral T2 high signal intensity than glioblastomas had. In visual assessment of peritumoral neoplastic cell infiltration using T2-weighted and diffusion-based images, all sequences differed significantly between the two groups. Exponential DWI had the highest sensitivity for the diagnosis of both glioblastoma (100%) and metastasis (70.6%). A combination of exponential DWI and ADC maps was optimal for the depiction of peritumoral neoplastic cell infiltration in glioblastoma. Conclusion: In the differentiation of glioblastoma from solitary metastatic lesions, visual morphologic assessment of tumoral and peritumoral regions using conventional MRI and diffusion-based techniques can also offer diagnostic information.

• Journal of the Korean Society of Industry Convergence
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• v.25 no.2_2
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• pp.219-232
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• 2022

The aim of this study is to provide the dynamic convergence index that reflected the inherent characteristics of the convergence phenomenon and utilized the nationally-funded R&D projects data, thereby suggesting useful information about the direction of the national convergence R&D strategy. The dynamic convergence index that we suggested was made of two indicators: persistency and diversity. From a time-series perspective, the persistency index, which measures the degree of continuous convergence of multidisciplinary nationally-funded R&D projects, and the diversity index, which measures the degree of binding with heterogeneous research areas. We conducted the empirical experiment with 151,248 convergence R&D projects during the 2015~2021 time period. The results showed that convergence R&D projects in both public health and life sciences appeared the highest degree of persistency. It was presumed that the degree of persistency has increased again due to the COVID-19 pandemic. Meanwhile, the degree of diversity has risen with combining with disciplinary such as materials, chemical engineering, and brain science areas to solve social problems including mental health, depression, and aging. This study not only provides implications for improving the concept and definition of dynamic convergence in terms of persistency and diversity for national convergence R&D strategy but also presented dynamic convergence index and analysis methods that can be practically applied for directing public R&D programs.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.2
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• pp.145-166
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• 2021

For several decades, sediment traps have served as one of the key tools for constraining the biological carbon pump (BCP), a process that vertically exports particulate organic carbon (POC) and associated biogenic materials from marine primary production in surface waters to the deep ocean interior. In this paper, I introduced the general methods, the current status of global sediment trap studies, and importance of it to understand the deep ocean carbon cycling. Recent studies suggest that sinking POC in the deep ocean are more complex and spatio-temporally heterogeneous than we considered. Especially researches those studied resuspended and laterally transported particles are presented. Researches that used organic (radiocarbon; ¹⁴C) and inorganic (Al) tracers to understand the oceanic POC cycling and the significance of resuspended particles are reviewed, and the importance of radiocarbon study by using MICADAS (Mini radioCarbon Dating Systems) is emphasized.

• Coupled systems mechanics
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• v.11 no.1
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• pp.55-78
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• 2022

The main aim of this paper is the identification of the model parameters for the constitutive model of concrete and concrete-like materials capable of representing full set of 3D failure mechanisms under various stress states. Identification procedure is performed taking into account multi-scale character of concrete as a structural material. In that sense, macro-scale model is used as a model on which the identification procedure is based, while multi-scale model which assume strong coupling between coarse and fine scale is used for numerical simulation of experimental results. Since concrete possess a few clearly distinguished phases in process of deformation until failure, macro-scale model contains practically all important ingredients to include both bulk dissipation and surface dissipation. On the other side, multi-scale model consisted of an assembly micro-scale elements perfectly fitted into macro-scale elements domain describes localized failure through the implementation of embedded strong discontinuity. This corresponds to surface dissipation in macro-scale model which is described by practically the same approach. Identification procedure is divided into three completely separate stages to utilize the fact that all material parameters of macro-scale model have clear physical interpretation. In this way, computational cost is significantly reduced as solving three simpler identification steps in a batch form is much more efficient than the dealing with the full-scale problem. Since complexity of identification procedure primarily depends on the choice of either experimental or numerical setup, several numerical examples capable of representing both homogeneous and heterogeneous stress state are performed to illustrate performance of the proposed methodology.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.33 no.2
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• pp.103-109
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• 2022

Background and Objectives The Voice Perceived Present Control scale (VPPC) has been developed to provide better insight into patients' perceived control over their thoughts or behaviors related to voice disorders. The objective of the present study was to validate the Korean VPPC (K-VPPC) by evaluating its internal consistency and reliability. Materials and Method All items of the English VPPC were translated into Korean. Content validity was analyzed through three Delphi survey rounds by an expert panel (n=44) with active clinical and research experience in treating dysphonic patients. Twenty-three patients with a heterogeneous diagnosis of dysphonia and twenty-three gender-matched vocally normal controls (total n=46) were asked to complete the K-VPPC and the Korean Voice Handicap Index-10 (KVHI-10). Psychometric properties including internal consistency and reliability were evaluated to examine the appropriateness of cross-cultural use of K-VPPC. Results Cronbach's alpha coefficient of K-VPPC was 0.89 for dysphonic patients, indicating good internal consistency in clinical samples. Furthermore, patients with dysphonia scored significantly lower on the total score of K-VPPC and higher on voice handicap than the vocally normal controls. Spearman's correlation coefficients indicated an inverse and moderate association between the K-VPPC and all domains of KVHI-10 (Spearman's r=-0.44- -0.68). Conclusion The findings of the current study indicated that the K-VPPC is a valid and reliable tool for the assessment of perceived control in Korean patients with dysphonia. Therefore, the K-VPPC could be a useful and complementary tool for the comprehensive evaluation of dysphonia, thereby improving care in Korean patients with voice disorders.

• Journal of Genetic Medicine
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• v.19 no.2
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• pp.85-93
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• 2022

Purpose: Cornelia de Lange syndrome (CdLS) is a rare genetically heterogeneous disorder caused by genetic variants of the cohesin complex. However, the diverse genetic etiologies and their phenotypic correlations in Korean patients with CdLS are still largely unknown. Hence, this study aimed to clarify the clinical characteristics and genetic background of Korean patients with CdLS. Materials and Methods: The medical records of 15 unrelated patients (3 males and 12 females) genetically confirmed to have CdLS were retrospectively reviewed. All individuals were diagnosed with CdLS using target gene analysis, whole-exome sequencing, and/or chromosomal microarray analysis. The clinical score (CS) was calculated to assess disease severity. Results: The median age at diagnosis was 1.7 (range, 0.0-11.8) years, and median follow-up duration was 3.8 (range, 0.4-11.7) years. Eight (53.3%) patients showed classic phenotypes of CdLS, two (13.3%) showed non-classic phenotypes, and five (33.3%) had other phenotypes sharing limited signs of CdLS. Fifteen causative variants were identified: NIPBL in five (33.3%, including 3 males), SMC1A in three (20.0%), SMC3 in three (20.0%), and HDAC8 in four (26.7%) patients. The CS was significantly higher in the NIPBL group than in the non-NIPBL group (14.2±1.3 vs. 8.7±2.9, P<0.001). Conclusion: We identified the clinical and genetic heterogeneity of CdLS in Korean patients. Patients with variants of NIPBL had a more distinctive phenotype than those carrying variants of other cohesin complex genes (SMC1A, SMC3, and HDAC8). However, further studies are warranted to understand the pathogenesis of CdLS as a cohesinopathy and its genotype-phenotype correlations.

• Journal of Genetic Medicine
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• v.19 no.2
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• pp.76-84
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• 2022

Purpose: Whole-exome sequencing (WES) has been a useful tool for novel gene discovery of various disease categories, further increasing the diagnostic yield. This study aimed to investigate the clinical utility of WES prospectively in undiagnosed genetic diseases. Materials and Methods: WES tests were performed on 110 patients (age range, 0-28 years) with suspected rare genetic diseases. WES tests were performed at a single reference laboratory and the variants reported were reviewed by clinical geneticists, pediatricians, neurologists, and laboratory physicians. Results: The patients' symptoms varied with abnormalities in the head or neck, including facial dysmorphism, being the most common, identified in 85.4% of patients, followed by abnormalities in the nervous system (83.6%). The average number of systems manifesting phenotypic abnormalities per patient was 3.9±1.7. The age at presentation was 2.1±2.7 years old (range, 0-15 years), and the age at WES testing was 6.7±5.3 years (range, 0-28 years). In total, WES test reported 100 pathogenic/likely pathogenic variants or variants of uncertain significance for 79 out of 110 probands (71.8%). Of the 79 patients with positive or inconclusive calls, 55 (50.0%) patients were determined to have good genotype-phenotype correlations after careful review. Further clinical reassessment and family member testing determined 45 (40.9%) patients to have been identified with a molecular diagnosis. Conclusion: This study showed a 40.9% diagnostic yield for WES test for a heterogeneous patient cohort with suspected rare genetic diseases. WES could be the feasible genetic test modality to overcome the diversity and complexity of rare disease diagnostics.

• Composites Research
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• v.22 no.5
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• pp.8-14
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• 2009

Interfacial evaluation of glass fiber reinforced carbon nanotube (CNT)-epoxy nanocomposite was investigated by micromechanical technique in combination with wettability test. The contact resistance of the CNT-epoxy nanocomposite was measured using a gradient specimen, containing electrical contacts with gradually-increasing spacing. The contact resistance of CNT-epoxy nanocomposites was evaluated by using the two-point method rather than the four-point method. Due to the presence of hydrophobic domains on the heterogeneous surface, the static contact angle of CNT-epoxy nanocomposite was about $120^{\circ}$, which was rather lower than that for super-hydrophobicity. For surface treated-glass fibers, the tensile strength decreased dramatically, whereas the tensile modulus exhibited little change despite the presence of flaws on the etched fiber surface. The interfacial shear strength (IFSS) between the etched glass fiber and the CNT-epoxy nanocomposites increased due to the enhanced surface energy and roughness. As the thermodynamic work of adhesion, $W_a$ increased, both the mechanical IFSS and the apparent modulus increased, which indicated the consistency with each other.

• Journal of Digital Convergence
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• v.20 no.1
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• pp.265-275
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• 2022

This study analyzes and categorizes the cases of military look's transitional design ideas in recent women's fashion collections, and derives characteristics. The research method is a theoretical review of military look and an analysis of fashion collection cases. The research results were classified into a total of six transformational design ideas. As a structural change in design, it is a decentralized type, a type of expansion and reduction, a change in the entire material, or a transition of some materials, and finally a type according to heterogeneous harmony and organic combination corresponding to styling. Finally, a total of three characteristics are the reconstruction of structural elements, the expansion of the metric of the second mix match, and the emotional fusion of styling. I hope that the study of the transformative type of idea of the new military look will be the driving force for creative design development and will be a basic study that can read the current status and changes of the times throughout fashion design.

• Korean Journal of Radiology
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• v.20 no.4
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• pp.649-661
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• 2019

Objective: To systematically review the evaluation of the diagnostic accuracy of pre-treatment apparent diffusion coefficient (ADC) and change in ADC during the intra- or post-treatment period, for the prediction of locoregional failure in patients with head and neck squamous cell carcinoma (HNSCC). Materials and Methods: Ovid-MEDLINE and Embase databases were searched up to September 8, 2018, for studies on the use of diffusion-weighted magnetic resonance imaging for the prediction of locoregional treatment response in patients with HNSCC treated with chemoradiation or radiation therapy. Risk of bias was assessed by using the Quality Assessment Tool for Diagnostic Accuracy Studies-2. Results: Twelve studies were included in the systematic review, and diagnostic accuracy assessment was performed using seven studies. High pre-treatment ADC showed inconsistent results with the tendency for locoregional failure, whereas all studies evaluating changes in ADC showed consistent results of a lower rise in ADC in patients with locoregional failure compared to those with locoregional control. The sensitivities and specificities of pre-treatment ADC and change in ADC for predicting locoregional failure were relatively high (range: 50-100% and 79-96%, 75-100% and 69-95%, respectively). Meta-analytic pooling was not performed due to the apparent heterogeneity in these values. Conclusion: High pre-treatment ADC and low rise in early intra-treatment or post-treatment ADC with chemoradiation, could be indicators of locoregional failure in patients with HNSCC. However, as the studies are few, heterogeneous, and at high risk for bias, the sensitivity and specificity of these parameters for predicting the treatment response are yet to be determined.