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Correlation of Proton Density Fat Fraction with Reference Fat Proportion: Repeatability and Reproducibility Analysis Across MRI Vendors
No full textCorrelation of Proton Density Fat Fraction with Reference Fat Proportion: Repeatability and Reproducibility Analysis Across MRI Vendors
Background: Previous studies on the validation of MRI-proton density fat fraction (PDFF) used MRI-based reference standards or employed fat phantoms with additives. In this study, we used a surfactant-free fat phantom to evaluate the accuracy of MRI-PDFF, including its repeatability and reproducibility across MRI scanners from different vendors, using the proportion of fat by weight as the reference standard.
Methods: A recently developed surfactant-free fat phantom composed of three fat proportions (10.9%, 20.1%, and 27.3% by weight) was employed to evaluate the performance of MRI-PDFF. PDFF values were estimated using MR spectroscopic sequences (HISTO) with Siemens 3.0 T, and MRI chemical shift sequences with three 3.0 T scanners: Architect (GE), Ingenia (Philips), and Vida (Siemens). Three scanning sessions were conducted at 2-month intervals, with each vendor’s protocol and a standardized protocol being applied twice per session. The accuracy of MRI PDFF in comparison with the reference fat proportion was evaluated using linear regression. Repeatability and reproducibility of the MRI-PDFF measurements were estimated by repeatability coefficients, reproducibility coefficients, and a mixed-effects linear model.
Results: MRI-PDFF demonstrated strong correlations (correlation coefficients, 0.971–0.999) with reference weight-based fat proportions across all MRI scanners, although the regression slopes varied considerably (regression slopes, 0.99–1.26). MRI-PDFF showed high repeatability on all scanners (repeatability coefficients, 0.19%–1.05% for vendor protocols; 0.50%–1.84% for standardized protocols), although reproducibility varied across vendors, increasing when measurements were pooled across all of them (reproducibility coefficients: 0.81%–0.86% for GE; 2.06%–3.05% for Philips; 2.07%–2.26% for Siemens; 3.04%–8.99% for pooled analysis). Significant differences were observed in PDFF measurements in all pairwise vendor comparisons (P < 0.001).
Conclusions: We evaluated the accuracy of MRI-PDFF using a surfactant-free fat phantom and confirmed high repeatability but lower reproducibility across vendors. To minimize variability and improve reliability during clinical trials, it may be preferable to use consistent MRI vendors, rather than a combination of different vendors.|연구제목: 팬텀의 기준 지방량과 자기공명영상의 Proton Density Fat Fraction간의 상관관계 및 장치별 반복성과 재현성 분석
연구배경: 이전 MRI-PDFF 검증 연구들은 MRI 기반의 참조 표준을 사용하거나 첨가제를 포함한 지방 팬텀을 사용했다. 이 연구에서 계면활성제를 첨가하지 않은 지방 팬텀의 중량 지방 비율을 참조 표준으로 하여 MRI-PDFF의 정확성을 평가하고, 다양한 MRI 기기간의 반복성과 재현성을 확인하고자 한다.
연구방법: 계면활성제를 첨가하지 않은 지방 팬텀(중량 기준 10.9%, 20.1%, 27.3% 지방 비율)을 사용하여 MRI-PDFF의 정확성을 평가했다. Siemens의 Vida 3.0 T에서는 HISTO 시퀀스를 사용한 MR 분광법으로, GE의 Architect, Philips의 Ingenia, Siemens의 Vida 등 세 가지 3.0 T 스캐너에서는 화학적 이동 시퀀스를 이용해 PDFF 값을 산출했다. 2개월 간격으로 세 번의 스캔 세션을 진행했으며, 각 벤더의 프로토콜과 표준화된 프로토콜을 세션당 두 번씩 적용했다. MRI PDFF의 정확성은 중량 지방 비율과 비교하여 선형 회귀분석을 사용해 평가하고, MRI-PDFF의 반복성과 재현성은 반복성 계수, 재현성 계수, 혼합 효과 선형 모델을 통해 평가하였다.
연구결과: MRI-PDFF는 중량 지방 비율과 모든 MRI 기기에서 강한 상관관계 (correlation coefficients, 0.971–0.999)를 보였으나, 회귀 기울기는 기기간 상당한 차이를 보였다 (regression slopes, 0.99–1.26). MRI-PDFF는 모든 기기에서 높은 반복성을 보였으나 (repeatability coefficients, 0.19%–1.05%: 벤더 프로토콜; 0.50%–1.84%: 표준화된 프로토콜), 재현성은 기기마다 차이가 있었고, 여러 기기의 측정값을 종합했을 때 재현성 계수가 증가했다(reproducibility coefficients, GE 0.81%–0.86%; Philips, 2.06%–3.05%; Siemens 2.07%–2.26%; 종합 3.04%–8.99%). 모든 기기 간 비교에서 PDFF 측정값의 유의미한 차이가 관찰됐다(P < 0.001).
연구결론: 계면활성제를 첨가하지 않은 지방 팬텀을 사용하여 MRI-PDFF의 정확성을 평가하였고, 기기 간 반복성은 높지만 재현성은 낮다는 것을 확인했다. 임상 시험에서는 여러 MRI 기기를 혼합하여 사용하는 것보다 일관된 MRI 기기를 사용하는 것이 변동성을 최소화하고 신뢰성을 높일 수 있다.Docto
A study on a model for predicting marine geotechnical properties using machine learning
No full text머신러닝을 이용한 해양 지반 물성치 예측 모 델에 관한 연구 蔚山大學校 大學院 建設環境工學科 심해 퇴적물의 특성을 예측하면 퇴적물 구성, 퇴적물 지층, 화학적 추적자 등 과거 의 해양 환경 조건에 대한 귀중한 통찰력을 얻을 수 있다. 그러나 심해 퇴적물은 지역에 따라 공간적 변동성이 크기 때문에 정확한 특성 예측이 어렵다. 이 연구에 서는 데이터 기반 머신러닝 모델을 사용하여 심해 퇴적물의 다섯 가지 특성을 예측 하는 프레임워크를 제안하였다. 다섯 가지 특성을 예측하기 위해 다섯 가지 시나리 오에 대해 전처리 및 하이퍼파라미터 튜닝 기법을 도입하였다. 또한 특징의 중요도 와 수심과 다섯 가지 특성 간의 관계를 평가하기 위해 샤플리 부가 설명을 선택하 였다. 그 결과 5가지 머신러닝 알고리즘 중 extreme gradient boost (XGB) 알고 리즘이 가장 높은 성능을 보인 것으로 나타났다. 또한 깊이와 압축파 속도는 공극 률, 입자 밀도, 방해석 함량, 열전도도를 예측하는 데 있어 가장 중요도가 높은 특 징과 두 번째로 중요한 특징인 것으로 평가되었다. 개발된 XGB 모델을 사용하여 불확실성 정량화를 통해 심도에 따른 5가지 특성을 예측한 결과, 본 연구에서 제시 한 데이터 기반 프레임워크가 심해저 퇴적물의 특성 예측에 활용될 수 있음을 시사 한다.Maste
Profile of plasma cytokine and placental methylation according to food allergy trajectories
No full textPurpose: The mechanisms related to the natural course of food allergy (FA) are not yet clearly known. We aimed to investigate the trajectories of FA and the differences in plasma cytokines and placental methylation according to the natural course of FA.
Methods: A total of 1,518 children from the COCOA (COhort for Childhood Origin of Asthma and Allergic Diseases) study, followed up until age 7, were classified into FA trajectories using group-based trajectory modeling. Blood eosinophil counts and total IgE levels were measured using cord blood and peripheral blood samples at ages 1, 3, and 7 years. In contrast, specific IgE levels to egg white and milk were measured only at ages 1, 3, and 7 years. Plasma cytokine levels at age 3 and 7 were analyzed. Placental methylation profiling was performed using Infinium MethylationEPIC BeadChip kits.
Results: Children were classified into 4 FA trajectories: no FA (87.3%); early remission (6.9%); persistent (4.6%); and late remission (1.1%). At age 3 and 7, the persistent FA trajectory showed higher interleukin (IL)-4, IL-5, and IL-6 levels than the no FA trajectory. IL-10 levels at age 3 were lower in the persistent FA trajectory compared to the late remission trajectory. In DNA methylation analysis, the Ribosomal Protein S6 Kinase A2 (RPS6KA2) and Germinal Center Associated Signaling And Motility Like (GCSAML) genes were significantly hypermethylated in the persistent FA trajectory compared to no FA and early remission trajectory (P < 0.05). GCSAML gene methylation level was positively correlated with all ages of total IgE, egg white-specific IgE at age 1, blood eosinophils at age 1, and IL5 at age 7 (all P < 0.05).
Conclusion: Increased methylation of the RPS6KA2 and GCSAML genes, lower IL-10 levels, and higher Th2 cytokines were associated with the persistent FA trajectory, potentially influencing its allergic inflammation and persistence.
Key Words: Food hypersensitivity, Trajectory, Cytokine, Methylation, Placenta, ChildDocto
Serum Proteomes and their Prognostic Values in Sepsis Patients Admitted to a Medical Intensive Care Unit: A Single-Center Study using SWATH-MS proteomics
No full textBackground: Despite advancements in critical care management, patients with septic shock still have poor clinical outcomes in the intensive care unit (ICU). Early prediction of mortality risk in patients with sepsis is essential for optimizing patient management and improving outcomes. Recent developments in proteomic techniques suggest opportunities to understand the pathophysiological heterogeneity of sepsis and provide precision medicine tailored to individual patients. Therefore, this study aims to evaluate the serum proteomic profiles of patients with sepsis using Sequential Window Acquisition of All Theoretical Mass Spectra proteomics and identify novel biomarkers for assessing sepsis severity and predicting patient outcomes in the ICU.
Methods: This retrospective cohort study included 217 adult patients diagnosed with bacterial sepsis who were admitted to a medical ICU at a single tertiary hospital between January 2011 and January 2020, along with 292 healthy controls. Proteomic analysis was performed to compare patients with sepsis to the healthy controls and analyze differences among sepsis subgroups. The subgroups were classified according to their outcome: early death (within 3 days), late death (after 3 days), and recovery (survived and discharged).
Results: Partial Least Squares Discriminant Analysis revealed that acute phase reactants, including c-reactive protein (CRP), serum amyloid A-1, and serum amyloid A-2, significantly discriminated patients with sepsis from healthy controls, whereas their levels did not differ among sepsis subgroups. Key protein markers distinguishing sepsis subgroups include β-actin (ACTB), fibronectin (FINC), metalloproteinase Inhibitor 1 (TIMP1), platelet factor 4 (PF4), and C-X-C motif chemokine 7 (CXCL7). Receiver operating characteristic analysis revealed that CRP had high diagnostic accuracy in discriminating patients with sepsis from healthy controls (area under the curve [AUC] 0.987, p < 0.001). However, they performed poorly in discriminating sepsis subgroups (AUC range 0.517–0.535). In contrast, ACTB, FINC, TIMP1, PF4, and CXCL7 showed higher AUCs in discriminating sepsis subgroups, especially between early death and recovery (AUC range 0.786–0.833). A 6-variable model including ACTB, FINC, CXCL7, TIMP1, PF4, and the SOFA score showed the highest AUC value of 0.903 for predicting in-hospital mortality. Multivariable Cox proportional hazards analysis revealed that increased ACTB (hazard ratio [HR] 1.21 [1.07–1.36], p = 0.002), decreased FINC (HR 0.88 [0.79–0.98], p = 0.024), higher SOFA scores (HR 1.08 [1.03–1.13], p = 0.002) and gram-negative sepsis (HR 1.42 [1.02–1.97], p = 0.038) were significantly associated with increased in-hospital mortality.
Conclusions: A novel set of biomarkers was identified in this study, including ACTB, FINC, CXCL7, TIMP1, and PF4, for assessing sepsis prognosis. The 6-variable model incorporating SOFA scores demonstrated a high prognostic value for in-hospital mortality, potentially enabling more accurate risk stratification for patients with sepsis in the ICU. Further studies using longitudinal samples and validation with complementary quantitative assays are warranted to improve the clinical applicability of these proteomic biomarkers.
Keywords: Sepsis, proteomics, SWATH-MS, biomarkers, prognosis, intensive care unitDocto
Cortical volumetric changes after cochlear implantation in postlingually deaf adults : correlation with speech perception abilities
No full textBackgrounds and Objective: The cochlear implantation (CI) has made it possible for deaf patients to regain hearing, but the outcomes vary significantly among individuals. One potential mechanism could be the cortical changes induced by hearing loss, which may ultimately affect the outcomes of CI. The preferred strategy for evaluating and analyzing volume changes in specific regions of the brain is to use various MRI-based neuroimaging analysis software tools. This study aims to analyze the volumetric changes in brain MRI before and after CI, focusing on the speech perception in postlingually deaf adults.
Study Design: We conducted a prospective cohort study with patients who had bilateral hearing loss and received unilateral CI. Based on the surgical side, patients were categorized into left and right CI groups. Volumetric T1-weighted brain MRI were obtained before and one year after the surgery. To overcome the artifact caused by the internal device in post-CI scan, image reconstruction method was newly devised and applied using the contralateral hemisphere of the pre-CI MRI data, to run FreeSurfer. We conducted within-subject template estimation for unbiased longitudinal image analysis, based on the linear mixed effect models comparing pre- and post-CI according to word recognition scores (WRS).
Results: A total of 16 patients were enrolled in the study. When analyzing the contralateral cerebral hemisphere before and after CI, a substantial increase in superior frontal gyrus and superior temporal gyrus (STG) volumes was observed in the left CI group. A correlation analysis was conducted to examine the relationship between volume changes and post-CI WRS. A positive correlation was observed in the STG in both groups. Creating a simulated hemisphere model involved flipping the right hemisphere of patients in the left CI group, revealing a notable increase in cortical volume in the STG associated with post-CI WRS.
Conclusion: This is the first study attempting longitudinal brain volumetry based on post-CI MRI scans. Better auditory performance after CI is associated with structural restoration in central auditory structures.Docto
Analysis of the Declining Birth Rate in China : Focusing on Population Policy and Socioeconomic Factors
No full text중국의 출산율 저하는 인구 정책의 급격한 변화와 사회경제적 구조 요인이 복합적으로 작용한 결과로, 단순한 경제적 선택을 넘어 제도적 신뢰와 감정 적 요인까지 포괄하는 다층적 현상이다. 본 논문은 ‘한 자녀 정책’ 이후 ‘세 자녀 정책’에 이르는 정책 전환 과정에서 나타난 제도 피로와 신뢰의 약화를 출산율 하락의 주요 요인으로 보고, 제도·구조·감정의 상호작용 속에서 청년 세대의 생애 전략을 분석하였다. 분석 틀로는 인구 전환 이론, 합리적 선택 이론, 경로 의존 이론, 정책 피 드백 이론을 종합적으로 활용하였으며, 이를 바탕으로 ‘생육제도 신뢰 메 커니즘’이라는 개념을 이론적으로 제시하였다. 실증적으로는 CFPS 데이터 를 참고하여 주거 비용, 교육 부담, 여성의 고학력화 및 경제활동 참여, 출 산에 대한 가치관 변화 등 다양한 사회경제적 요인의 작동 양상을 고찰하였 다. 본 연구는 출산율 저하를 제도의 설계 부족이나 경제적 요인의 결과로만 해석하는 기존 접근을 넘어, 제도 신뢰의 상실과 감정 주체화가 결합된 복 합적 구조로 파악하며, 향후 출산 정책의 실효성과 지속 가능성을 확보하기 위한 제도적 재구성과 정책적 시사점을 도출하고자 한다. 키워드: 출산율 저하; 청년 세대 ; 사회경제적 요인; 인구 정책; 제도 신뢰|The decline in China’s fertility rate is the result of a complex interplay between abrupt changes in population policy and broader socioeconomic structural factors. Rather than being a matter of individual economic decision-making alone, it constitutes a multilayered phenomenon encompassing weakened institutional trust and emotional dimensions. This study identifies institutional fatigue and the erosion of policy trust— emerging during the transition from the one-child policy to the three-child policy—as critical drivers of fertility decline. It further analyzes how the interaction of institutional, structural, and emotional variables shapes the life strategies of the younger generation. To this end, the research adopts an integrated analytical framework that draws on demographic transition theory, rational choice theory, path dependence theory, and policy feedback theory. Building upon this framework, the study introduces the concept of a "fertility governance trust mechanism" as a theoretical contribution. Empirical analysis, based on CFPSdata, explores how various socioeconomic factors—such as rising housing and educational costs, increased female educational attainment and labor force participation, and shifting values regarding marriage and childbirth—affect fertility decisions. By going beyond conventional interpretations that attribute low fertility solely to institutional design flaws or economic burdens, this study positions fertility decline within a composite structure shaped by the loss of policy trust and the emergence of affective subjectivity. Ultimately, it seeks to draw policy implications and propose directions for institutional reform to enhance the effectiveness and sustainability of future fertility policies in China. Keywords： Declining fertility rate； Young generation； Socioeconomic factors； Population policy；Institutional trustMaste
Developing a locally-based smart farm service model for Creating Shared Value
No full text산업화와 도시화로 인해 인구가 도심에 집중되면서 농촌의 인구가 크게 줄 어들고 농가 인구가 꾸준히 고령화되면서 농가 인력 부족 문제가 심화하였다. 또한, 지구온난화로 인한 기후변화는 국내 농업에도 직접적인 영향을 미치고 있다. 전반적인 기후 상승으로 인해 농작물의 재배 적지가 변화하고 농산물의 생산량도 증가하거나 감소하는 등 영향을 보인다. 이에 대한 해결책으로 최근 스마트팜이 주목받고 있다. 스마트팜은 농산물이 자라는 환경을 ICT, 빅데이 터, AI 등의 4차 산업기술을 활용해 자동으로 통제하고 관리하는 농장을 의 미한다. 스마트팜은 기존 농업과 비교해 노동강도가 낮고 농장 외부 환경의 영향을 받지 않기 때문에 안정적인 생산량을 기대할 수 있다. 본 연구는 이러 한 시대적 상황에서 떠오르고 있는 스마트팜에서 비즈니스 가치뿐만 아니라 사회적·환경적 가치를 함께 달성할 수 있는 공유가치 창출(CSV)을 위한 스 마트팜 서비스 모델을 개발하는 것을 목표로 하였다. 본 연구의 방법은 우선 국내 농업 현황에 대해 파악한 후 스마트팜 및 CSV에 대해 문헌 조사를 통해 이론적 배경을 파악하였다. 이후 서비스 모델 개발을 위한 연구모델을 제안하였다. 본 연구에서 설계한 연구모델은 PEST-CSV 분석으로 기존의 PEST 분석에서 도출된 기회 요인에 CSV를 위한 3가지 전략을 결합한 모델이다. PEST-CSV를 통해 도출된 전략을 바 탕으로 서비스 모델 아이디어를 구상하였으며 서비스 모델 개념도를 통해 도 식화하였다. 이후 전문가 인터뷰를 통해 서비스 모델 개념도를 평가하였으며 전문가 의견을 반영한 최종 서비스 모델을 제안하였다. 연구 결과, 우선 PEST-CSV 분석을 통해 CSV를 위한 스마트팜 전략 5가지를 도출할 수 있 었다. 도출된 전략을 바탕으로 스마트팜 서비스 모델을 운영하는 농업법인 자 사와 지자체, 지역 내 스마트팜 혁신밸리와의 지역 클러스터를 형성하여 청년 농을 위한 지역 기반 공유형 스마트팜을 제안할 수 있었다. 이후 관련 분야의 전문가 인터뷰를 통해 본 서비스 모델을 평가하였고 보완이 필요한 부분에 대 한 의견을 수렴하여 최종 서비스 모델을 제안하였다. 본 연구의 결과물은 지자체 주관 스마트팜 확산 사업의 기획 및 스마트팜 전문기업의 새로운 수익모델 개발 시 기초자료로 활용될 수 있을 것이다. 그 러나 본 연구가 제안하는 서비스 모델을 창업 등을 통해 실행하였을 때 원활 한 작동이 가능한지에 대한 실험 및 검증이 이루어지지 못했다는 점에서 한계 가 있었다. 후속 연구에서는 경영학적 심층적 연구를 통해 목표와 성과 항목 을 더욱 구체화하고 현행 농업과 스마트팜 관련 법제에 대한 심층적인 조사와 분석을 통해 실행할 수 있는 서비스 모델로 구현할 수 있을 것으로 기대된다.Maste
Effect of age and gender in rates of achieving minimal clinically important difference and patient-acceptable symptom state 2 years after arthroscopic superior capsular reconstruction
No full textPurpose: This study aimed to evaluate patient-reported outcome measures (PROMs) and the effects of gender and age on achieving clinically significant outcomes in patients undergoing arthroscopic superior capsular reconstruction (ASCR) with a minimum 2-year follow-up.
Methods: Patients undergoing ASCR for irreparable rotator cuff tear between 2013 and 2020 were reviewed. Preoperative and minimum 2-year postoperative PROMs were collected, including American Shoulder and Elbow Surgeons (ASES), Constant, single assessment numeric evaluation (SANE), and visual analog scale (VAS) scores. Minimal clinically important difference (MCID) and patient-acceptable symptomatic state (PASS) were calculated for each functional score and analyzed according to age and gender. The percentages of patients achieving MCID and PASS were recorded.
Results: The study included 83 patients, with a mean follow-up of 3.5 ± 1.4 years. Significant improvements were found in ASES, Constant, SANE, and VAS for all groups based on gender and age. Based on receiver-operating characteristic curves, all scores had acceptable areas under the curve for PASS. Values for PASS and MCID were 81.5 and 10.3 for ASES; 61.5 and 6.2 for Constant; 82.5 and 11.5 for SANE and 1.5 and 1.1 for VAS, respectively. Analysis of achieving MCID and PASS showed no difference between the groups in the majority of outcome measures. However, female patients achieved the SANE thresholds for PASS at significantly higher rates than male patients. Patients ≥65 years old achieved ASES and Constant thresholds for MCID at significantly higher rates than patients ˂65 years old.
Conclusion: Most patients achieved MCID and PASS at a 2-year follow-up. Patients showed comparable rates of MCID and PASS achievement on most outcome tools based on age and gender. Female patients achieved PASS on SANE at significantly higher rates than male patients and older patients achieved MCID on ASES and Constant at higher rates than young patients. Thus, age is a stronger factor for achieving MCID than gender.
Level of evidence: Level II
Factors Influencing the Diagnostic Performance of Repeat Endoscopic Ultrasound-Guided Fine-Needle Aspiration/Biopsy after the First Inconclusive Diagnosis of Pancreatic Solid Lesions
No full textBackground/aims: Endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/B) is essential in diagnosing solid pancreatic lesions (SPLs), but without rapid on-site evaluation (ROSE), a repeat EUS-FNA/B is crucial for clarifying an inconclusive diagnosis. We aimed to evaluate factors associated with improved diagnostic performance of repeat EUS-FNA/B for initially inconclusive SPL diagnoses without ROSE.
Methods: Of 5,894 patients subjected to EUS-FNA/B, 237 (4.0%) with an initially inconclusive diagnosis of SPLs were retrospectively enrolled from five tertiary medical centers between January 2016 and June 2021. Diagnostic performance and procedural factors of EUS-FNA/B were analyzed.
Results: The diagnostic accuracies of first and repeat EUS-FNA/B were 96.2% and 67.6%, respectively. Of 237 patients with an inconclusive diagnosis from initial EUS-FNA/B, 150 were pathologically diagnosed after repeat EUS-FNA/B. In multivariate analysis of repeat EUS-FNA/B, tumor location (body/tail vs head: odds ratio [OR], 3.74; 95% confidence interval [CI], 1.48 to 9.46), number of needle passes (≥4 vs ≤3: OR, 4.80; 95% CI, 1.44 to 15.99), needle type (FNB vs FNA: OR, 3.26; 95% CI, 1.44 to 7.36), needle size (22 gauge vs 19/20 gauge: OR, 2.35; 95% CI, 1.19 to 4.62), and suction method (suction vs others: OR, 5.19; 95% CI, 1.30 to 20.75) were associated with a significantly improved diagnostic performance.
Conclusions: Repeat EUS-FNA/B is essential for patients with an inconclusive EUS-FNA/B without ROSE. To improve the diagnostic performance of repeated EUS-FNA/B, it is recommended that 22-gauge FNB needles, ≥4 needle passes, and suction methods are used
Exploring Development Strategies for the Secondhand Clothing Industry through Comparative Analysis of Blog Posts on Secondhand and Thrift Clothing Purchases
No full textThis study explored development strategies for the secondhand clothing industry by understanding consumer attitudes toward secondhand and thrift clothing purchases. Blog posts were compiled and analyzed using TEXTOM for word analysis and clustering. The results are as follows. Word analysis revealed that, aside from the commonly used terms for clothing purchases, the words collected from “secondhand clothing purchases” and “thrift clothing purchases” were different. Consumers tended to perceive the purchase of secondhand clothing as a transaction, whereas the purchase of thrift clothing was viewed as an interesting shopping experience. Second, the clustering analysis of secondhand clothing resulted in five distinct groups: “Impact of clothing consumption on the global environment and the importance of sustainable consumption,” “Global trend of online secondhand clothing transactions,” “Satisfied reviews of secondhand clothing purchases,” “Purchasing secondhand clothing through flea markets,” and “Reviews of Japanese secondhand clothing purchase/auction proxy services.” The clustering analysis of thrift clothing also yielded five groups: “Review of a visit to a warehouse-style thrift store,” “Thrift shopping malls dealing with vintage clothing,” “Promotion of various items and brands sold in stores,” “High-quality luxury thrift with a vintage feel,” and “Promotion and introduction of a thrift clothing company’s store.