Background: Hair drying is a routine cosmetic practice; however, excessive heat exposure and non-uniform airflow can compromise cuticle integrity, degrade hair sensory properties, and induce scalp discomfort. This study aimed to (i) identify a practical thermal window that minimizes perturbation of hair fiber surface and quantify late-stage thermal amplification during the drying process using percentage-based analysis. Methods: Temperature-dependent hair fiber surface morphology was examined by scanning electron microscopy (SEM) after controlled exposure to 41°C, 60°C, 80°C, and 90°C using virgin and chemically damaged hair. The drying efficacy was assessed using the surface and internal moisture indices under airflow shaping (test) and uniform airflow (control) conditions. Hair fluttering (maximum angular displacement) was evaluated before and after drying under warm-cool alternating (60°C-80°C) versus constant hot airflow (80°C). Results: SEM revealed temperature-dependent cuticle disruption, with markedly greater surface perturbation at 90°C than at 80°C. Infrared thermography demonstrated pronounced late-stage thermal amplification: at 150 seconds, the surface temperature increased by 295% (from 24.2°C to 72.0°C) at 90°C, compared with 207% (from 24.2°C to 50.7°C) at 80°C. Airflow shaping promoted preferential surface moisture removal (–13.6%) while limiting internal dehydration (–9.4%), whereas the control condition exhibited minimal surface drying (–4.6%) but substantial internal moisture loss (–22.2%). Warm-cool modulation increased hair fluttering by +11.0%, whereas constant hot airflow reduced it (–3.7%). Conclusion These findings indicate that spatial and temporal control of heat delivery represents a clinically relevant design strategy beyond the nominal temperature specification in hair-drying devices.

BACKGROUND/OBJECTIVES: Supplementation of nicotinamide adenine dinucleotide (NAD) precursors has been investigated for its potential to counteract age-related physiological decline. While decreased NAD + level is associated with conditions such as obesity and dyslipidemia, few studies have explored its metabolic impact in relatively young animals.Here, we hypothesized that nicotinamide mononucleotide (NMN) could alleviate highfat diet-induced metabolic stress in young mice and sought to elucidate the underlying mechanisms.MATERIALS/METHODS: We first conducted a secondary analysis of hepatic transcriptome datasets from multiple NMN intervention studies to identify target pathways. Next, 11-weekold lean and obese C57BL/6N mice administrated NMN (500 mg/kg/day) for 1 mon were analyzed for metabolic parameters and gene expression for the target pathways. In vitro study using AML12 cell line was then conducted to confirm the effects of NMN. Additionally, transcriptomic data from liver-specific nicotinamide phosphoribosyltransferase (NAMPT)-deficient mice were analyzed to examine the relationship between NAD + metabolism, endoplasmic reticulum (ER) stress, and circadian rhythm. RESULTS: The secondary analysis of hepatic transcriptome datasets revealed potential target pathways related to circadian regulation and hepatic ER stress. In mouse study, short-term NMN administration significantly decreased body weight and fat mass. NMN also alleviated hepatic ER stress response in vivo and in vitro. Additional analysis revealed that the mice with diet-induced metabolic stress or NAMPT deficiency led to phase shifts of the hepatic circadian core clock oscillation by advancing the peak time, while time-restricted feeding shifted the opposite, indicating the metabolic regulation of the circadian phase. CONCLUSION Short-term NMN administration effectively attenuated obese condition in young mice and mitigated hepatic ER stress. The altered ER stress was regulated by NAMPT, potentially through the phase shift of the hepatic circadian rhythm.

BACKGROUND/OBJECTIVES: Postpartum bone metabolism undergoes substantial alterations based on breastfeeding status. Research on maternal calcium intake and bone recovery, particularly among Asian women, remains limited. This study investigated postpartum change in bone mineral density (BMD) and its association with calcium intake during late pregnancy and post-delivery according to breastfeeding status. SUBJECTS/METHODS: Thirty-six women (22 breastfeeding, 14 non-breastfeeding) underwent dual-energy X-ray absorptiometry 3 times: 1) within 3 days of delivery, 2) at 6 mon postpartum for non-breastfeeding women or within 1 mon of weaning for breastfeeding women, and 3) at 12 mon postpartum. Dietary calcium intake was evaluated using a food frequency questionnaire and dietary supplement survey at all visits. Association between calcium intake with percentage change in BMD (%ΔBMD) was assessed by linear regression. RESULTS: The BMD at the lumbar spine, total hip, femoral neck, and trochanter significantly decreased during breastfeeding, whereas non-breastfeeding women displayed increased BMD at the femoral neck at 6 mon postpartum. In non-breastfeeding women, postpartum calcium intake was positively associated with %ΔBMD at the total hip, femoral neck, and intertrochanter (P < 0.05). Few significant associations were observed between %ΔBMD and late pregnancy intakes across all women, regardless of breastfeeding status. At 12 mon, BMD in breastfeeding women recovered to delivery levels, while non-breastfeeding women maintained their BMD observed at 6 mon postpartum. CONCLUSION Postpartum calcium intake is positively associated with bone recovery in non-breastfeeding women, suggesting that its effects on bone recovery potentially vary with lactation status.

Background: Epidermal growth factor (EGF) is widely applied in dermatology for its regenerative effects; however, its clinical utility is limited by low stability and high production costs.To overcome these limitations, we developed a novel probiotic-derived epidermal growth factor (pEGF) by engineering Pediococcus pentosaceus CBT SL4 to express and secrete EGF. Objective: To investigate the anti-photoaging effects of topical pEGF in a ultraviolet B (UVB)-irradiated mice by assessing histological and molecular changes related to collagen synthesis, extracellular matrix (ECM) remodeling, oxidative stress, and inflammation. Methods: SKH1 hairless mice were exposed to UVB for twelve weeks to induce photoaging and treated with topical 10% pEGF cream from week 9 to 12. Skin samples were analyzed using dermoscopy, histology, immunohistochemistry, quantitative real-time polymerase chain reaction, western blotting, and proteomics to evaluate morphological and molecular alterations in ECM components and inflammatory markers. Results: Topical pEGF treatment improved skin texture and reduced wrinkles. Histological evaluation revealed that EGF significantly attenuated UVB-induced epidermal thickening and restored collagen density, with the strongest effects observed in the pEGF group. Molecular analysis showed downregulation of matrix metalloproteinases (MMPs; MMP-1, MMP-3), upregulation of collagen (type I collagen, type III collagen) and tissue inhibitors of metalloproteinases (TIMPs; TIMP-1, TIMP-2). Additionally, pEGF reduced pro-inflammatory cytokines (tumor necrosis factor-α, interleukin-1β) and oxidative stress markers. Conclusion pEGF demonstrated potent anti-photoaging effects through ECM restoration, inflammation modulation, and barrier reinforcement. These findings support the therapeutic potential of pEGF as a stable, cost-effective alternative to conventional EGF in dermatological applications.

Background: A systematic evaluation of potential living liver donors is essential to ensure donor safety and optimize recipient outcomes in living donor liver transplantation (LDLT). This study aimed to assess donor acceptance rates and reasons for disqualification among individuals evaluated for LDLT at a high-volume transplant center over a one-year period. Methods: We retrospectively reviewed 1,087 potential living liver donors who presented for LDLT evaluation in 2023. Of these, 991 candidates advanced beyond the initial screening (Stage 1) and underwent comprehensive clinical, imaging, and pathological assessments (Stages 2 and 3). Candidates who discontinued after Stage 1 were excluded due to the absence of documented reasons for non-progression. Results: Among the 991 candidates who proceeded beyond initial screening, 473 (47.7%) completed the full donor evaluation, of whom 466 were judged to be suitable donors. Among suitable donors, 384 (82.4%) proceeded to donor hepatectomy, whereas 82 did not, primarily due to recipient-related factors such as clinical deterioration or withdrawal of consent. Donor ineligibility was determined in 422 candidates (42.6%), most commonly due to inadequate remnant liver volume (52.8%), hepatic steatosis (20.6%), and insufficient graft size (10.2%). Among candidates undergoing Stage 2 evaluation, 162 (16.3%) failed to meet steatosis criteria; 126 were excluded solely for steatosis and advised weight reduction, and 39 subsequently became eligible and successfully donated. Conclusion In this high-volume LDLT center, donor disqualification was primarily driven by remnant liver volume and hepatic steatosis. Targeted interventions such as weight reduction enabled successful donation in a subset of initially ineligible candidates, underscoring the importance of individualized donor evaluation and pre-donation optimization.

Background: We developed a simplified variant of the ADV score, the AFP-PIVKAII (AP) score for post-transplant hepatocellular carcinoma (HCC) prognosis, which considers only AFP and PIVKA-II levels excluding morphometric tumor size information from the ADV score. This study investigated the prognostic performance of the AP score in predicting HCC recurrence and overall survival (OS) after living donor liver transplantation (LDLT). Methods: We analyzed 843 patients with HCC who underwent LDLT between 2006 and 2015, assessing HCC recurrence and OS in relation to AP score. Results: The median pretransplant AFP and PIVKA-II levels were 12.8 ng/mL and 27 mAU/mL, respectively. The median and mean AP scores were 2.6 log (range: 0.6–9.2 log) and 2.9±1.1 log, respectively. The 5-year time-dependent area under the receiver operating characteristic curve for the AP score in predicting post-transplant HCC recurrence was 0.672 (p<0.001). HCC recurrence and OS curves along AP score intervals of 1.0 log showed statistical differences in accordance with the AP scores (both p<0.001). Using a Youden index J-derived AP score cutoff of 4.0 log, two-tiered groups (ADV <4.0 log vs. ADV ≥4.0 log) showed statistically significant differences in HCC recurrence and OS (both p<0.001). Harrell’s c-indices for AP score with cutoff of 4.0 log and ADV scores with cutoff of 5.0 log regarding HCC recurrence and OS were similar. Conclusion The AP score functions as an integrated surrogate marker for predicting post-transplant outcomes in patients with HCC undergoing LDLT. It may serve as a simplified alternative to the ADV score, particularly in patients with small HCCs.

Purpose: Technological advancements have enabled reduced-port robotic systems, enhancing the benefits of robotic surgery. This study compared the surgical outcomes of conventional multiport (5 ports), single-site (2 ports), and singleport (2 ports) robotic gastrectomy for gastric cancer. Methods: A prospectively collected database was retrospectively reviewed for patients who underwent robotic distal subtotal gastrectomy between January 2010 and August 2022 at Severance Hospital, Yonsei University Health System. The initial 20 cases from each group (multiport, single-site, and SP) were analyzed, focusing on demographics, surgical procedures, pathological results, and postoperative outcomes. The “textbook outcome” metric was employed to assess surgical quality. Results: The SP group showed lower visual analog pain scale compared to the multiport and single-site groups (3.5, 4.4, and 4.3, respectively, P = 0.017), faster time to first flatus (2.0, 2.7, and 2.8 days, respectively; P < 0.001), and shorter hospital stays (3.5, 6.2, and 5.5 days, respectively; P < 0.001). No significant differences were observed in major complications, unplanned intensive care unit care, readmission, or mortality between the groups. The rate of patients achieving textbook outcomes were 85.0% for the multiport group, 100% for the single-site group, and 95.0% for the SP group (P = 0.310). Conclusion Reduced-port robotic gastrectomy, including single-site and SP, has shown surgical safety with a high proportion of patients meeting textbook outcomes. The SP system demonstrated less pain and faster recovery, aligning with minimally invasive surgical goals. Therefore, the SP system could be a reliable and safe option for robotic gastrectomy, offering enhanced recovery without compromising surgical quality.

Purpose: This study was performed to predict individualized treatment strategies in ruptured abdominal aortic aneurysm (rAAA) by estimating the survival benefit of endovascular aneurysm repair (EVAR) and open surgical repair (OSR) based on anatomical and physiological features using a causal inference model. Methods: This retrospective study included 45 patients with de novo rAAA who underwent EVAR or OSR between 2012 and 2024. Thirty-three variables were analyzed. The model estimated individualized treatment effects (ITE) for 30-day survival.Model interpretability was assessed using Shapley Additive Explanations (SHAP) analysis. Five-fold cross-validation, receiver operating characteristic (ROC) analysis, and calibration plots were used for model evaluation. A clinical decision tree was developed to derive simplified decision rules. Results: The mean ITE was 0.22 ± 0.42, with 33% of patients classified as OSR-benefit candidates. SHAP analysis revealed that suprarenal angle, infrarenal angle, iliac anatomy, and proximal neck characteristics strongly influenced treatment effects. However, some predictors, such as low hemoglobin and systolic blood pressure favoring OSR, conflicted with clinical intuition. ROC analysis showed an area under the curve of 1.00, but calibration suggested overfitting due to a small sample size. Treatment-matched patients had a higher 30-day mortality rate than mismatched patients, suggesting potential bias or unmeasured confounding. The decision tree identified clinically relevant features but displayed structural inconsistencies and impractical cutoff values due to the limited sample size. Conclusion The X-learner model demonstrated the feasibility of individualized treatment prediction in rAAA but suffered from overfitting and limited generalizability. Validation with larger multicenter cohorts is necessary to confirm clinical applicability.

Purpose: Due to its rarity, treatment guidelines for appendiceal cancer have traditionally followed those established for colorectal cancer, despite showing distinct histologic and clinical features. This study aimed to compare the clinicopathologic characteristics and long-term oncologic outcomes of appendiceal cancer with those of right-sided colon cancers. Methods: We retrospectively reviewed the records of patients with stage I–III appendiceal, cecal, or ascending colon cancer who underwent curative resection between 2010 and 2020 at our center. A 1:3:3 exact matching for age, sex, TNM stage, and adjuvant chemotherapy was performed. Survival outcomes were analyzed using the Kaplan-Meier and Cox regression methods. Results: Overall, 245 patients with appendiceal cancer (n = 35), ascending colon cancer (n = 105), and cecal cancer (n = 105) were analyzed. Appendiceal cancer exhibited a higher proportion of T4 tumors and fewer harvested lymph nodes compared with ascending or cecal cancers. The mean follow-up duration was 9.5 years. The 5- and 10-year overall survival rates were lower in appendiceal cancer (66.2% and 52.9%) than in ascending (91.2% and 78.4%) or cecal cancer (88.5% and 78.3%). Similarly, the 10-year disease-free survival rate was lower in appendiceal cancer (59.2%) compared with ascending (83.1%) and cecal cancers (78.4%). Cox regression analysis identified age (≥65 years), perforation, nodal metastasis, and lymphovascular invasion as independent predictors of poor prognosis. Conclusion Appendiceal cancer exhibited significantly worse long-term survival compared to cecal or ascending colon cancer. Tumor perforation, nodal metastasis, and lymphovascular invasion were adverse prognostic factors for overall and disease-free survival.

Purpose: Neoadjuvant chemotherapy (NAC) significantly revolutionized the management of locally advanced breast cancer, especially in human epidermal growth factor receptor 2 (HER2)-positive and triple-negative subtypes. However, its effectiveness is limited in estrogen receptor (ER)-positive, HER2-negative breast cancer. This study investigates the clinical response and prognosis of ER-positive, HER2-negative breast cancer after NAC. Methods: The clinicopathological characteristics and treatment responses of 149 patients with ER-positive, HER2-negative breast cancer treated with NAC and surgery at The Catholic University of Korea, Seoul St. Mary’s Hospital between 2018 and 2023 were retrospectively analyzed. Pathologic complete response (pCR) was defined as the absence of invasive tumors (ypT0/is, ypN0). Disease-free survival (DFS) and overall survival (OS) were analyzed using Kaplan-Meier methods, stratified by age (≤50 years vs. >50 years). Results: Among 149 patients, 13 (8.7%) achieved pCR, 87 (58.4%) attained partial responses, 40 (26.8%) had stable disease, and 9 (6.0%) experienced progressive disease. RECIST responses differed significantly by age (P = 0.003). DFS (P = 0.011) and OS (P = 0.005) were significantly associated with clinical response in patients aged ≤50 years. Post-NAC Ki-67 was associated with DFS (P = 0.013) but not OS (P = 0.083) in patients aged ≤50 years. Clinical responses and post-NAC Ki-67 were not associated with DFS (P = 0.544) or OS (P = 0.569) in patients aged >50 years. Conclusion In ER-positive, HER2-negative breast cancer, clinical responses and post-NAC Ki-67 were significant prognostic factors in patients aged ≤50 years but not in older patients. These findings highlight the need for tailored therapeutic approaches that consider age-specific prognostic differences.