University of Nagasaki

This study aimed to compare the dosimetric parameters of the simultaneous integrated boost (SIB) technique using volumetric modulated arc therapy (VMAT) guided by 99mTc-labeled diethylenetriamine pentaacetate-galactosyl human serum albumin (99mTc-GSA) single-photon emission computed tomography (SPECT) image with those of conventional three-dimensional conformal radiotherapy (3D-CRT). Five patients with diffuse liver metastases underwent 99mTc-GSA SPECT and computed tomography (CT) imaging before RT planning. A SPECT threshold was used for determining the functional liver structure (FLS). The 3D-CRT plan included anterior-posterior opposed beams. The prescribed dose was 8 Gy in one fraction, with a goal of 95% of the planning target volume (PTV), D95, receiving at least 95% of the prescribed dose. The absorbed dose received by 2 cm3 of organ at risk (OAR) volume (D2cc) was below 10 Gy. The VMAT plan comprised two or three arcs. The goals for the PTV and OARs matched those of 3D-CRT. The PTV dose in SIB (PTVboost) defined according to FLS was optimized at an isodose line [~80% of the maximum dose (Dmax)] received at D95 of PTVboost. Two plans were compared using the dose-volume histogram parameters of PTV, PTVboost, FLS, and OARs. Dosimetric parameters including Dmean, Dmax, V110%, and V120% for PTV were significantly higher in the VMAT plan than in the 3D-CRT plan. Likewise, for PTVboost, the VMAT plan had significantly higher values of dosimetric parameters (D95, Dmean, Dmax, V110%, and V120%) than the 3D-CRT plan. The FLS and OAR parameters did not significantly differ between the two plans, except for the spinal cord. 99mTc-GSA SPECT image-guided VMAT planning using SIB allows selective target dose increase in palliative radiotherapy for diffuse liver metastases.

Mental health challenges are a significant concern among students and trainees in medical fields worldwide, including Japan, where high psychological distress is prevalent. This pilot study examined the feasibility and impact of a 6-day creative arts program designed for Japanese medical and international graduate students. A total of 14 students provided informed consent to participate in the study. Employing a convergent mixed-methods design, quantitative and qualitative data were collected and analyzed independently. Students completed the Comprehensive Inventory of Thriving (CIT) before and after the program to assess changes in psychological well-being. Pre-post differences were examined using paired t-tests. Qualitative data collection included post-program surveys, semi-structured interviews, and six-month follow-up interviews. We conducted thematic analysis to identify key patterns in student experiences. We then examined whether changes in CIT scores correlated with the frequency of qualitative codes to identify potential points of convergence between the two datasets. Thirteen students completed all major components of the study, with an average attendance of 5.2 out of 6 sessions. CIT scores significantly increased from before (M = 198.0, SD = 29.9) to after completing the program (M = 217.3, SD = 20.2), t(12) = -4.89, p = .0004, indicating a significant increase in thriving. Thematic analysis yielded three core themes: (1) Discovery through the underexplored parts of self and surroundings, (2) Rapid community bonding through inspiration, and (3) Creativity as a disruption to stress. Six-month follow-up interviews revealed additional themes related to enduring impact from the intervention: Applying creative insights into everyday life and mindsets. Through the convergent mixed-methods analysis, one pairing reached statistical significance: the change over time in the CIT subscore ‘Meaning’ was strongly correlated with the qualitative code “Out of the ordinary” (r = + 0.868), suggesting that increases in participants’ sense of meaning were strongly associated with the frequency of experiences that felt “Out of the ordinary” during the creativity program. The findings suggest that a creative arts program for medical students is both feasible and effective in promoting well-being, enhancing stress management skills, and deepening self-awareness. The program shows promise for integration into medical education to support students’ holistic development and mental health.

ABSTRACT Metal‐free polymerization is required to prevent contamination of polymeric materials by residual metal catalysts. In this study, the ring‐opening polymerization (ROP) of ε ‐caprolactone (CL) is investigated under bulk conditions at 100°C using benzyl alcohol (BnOH) as the initiator and seven environmentally benign organic acids (EBOAs) as activators (catalysts). In all cases, ROP yields poly( ε ‐caprolactone) (PCL) with narrow polydispersities ( Ð ). Kinetic analysis shows first‐order behavior, indicating a controlled process. The reaction rate constant ( k ) correlates with the acidity (p K a ) of EBOAs, with stronger acids (lower p K a ) exhibiting higher catalytic activity among those tested. Substituting BnOH with alternative alcohol initiators produces PCL bearing well‐defined heterotelechelic end groups, such as ally or polyethylene glycol moieties. Hydroxy‐terminated PCL enables further post‐polymerization, including chain extension and block polymerization (poly( ε ‐caprolactone)– b– poly( δ ‐valerolactone); PCL– b– PVL) with δ ‐valerolactone using EBOAs, while preserving narrow Ð . Moreover, the composition unit in PCL– b– PVL can be tuned by selecting EBOAs of different acidity, directly influencing catalytic activity. This controlled EBOA‐based system is useful for applications where metal contamination must be avoided, such as polymeric biomaterials.

Introduction: Hazard scenarios during torrential rain disasters in Japan involve a high proportion of elderly people and accidents indoors. One of the reasons for this is the lack of available workers at welfare facilities for the elderly. The purpose of this study is to examine the factors that affect the attitudes of staff toward onsite attendance at welfare evacuation shelters. Methods: Thirty welfare evacuation shelters were randomly sampled from 89 shelters in a city, and a self-administered, anonymous questionnaire survey was conducted by mail. The levels of disaster preparedness and disaster awareness were measured from responses, and their relationship to attitudes toward onsite attendance during disasters was analyzed. Results: A total of 113 staff subjects were analyzed. Responses of walking to work in the event of a disaster (p=0.002, x2test), being aware of a disaster manual (p=0.004, x2test), and having defined roles at the facility in the event of a disaster (p=0.034, x2test) were associated with onsite attendance. Disaster preparedness was associated with the ability to visualize disaster situations (p=0.009, Mann-Whitney U test), the ability to sense impending disasters (p=0.019, Mann-Whitney U test), and concern regarding disasters (p=0.001, Mann-Whitney U test). Compared to non-attendees, attendees were more concerned (OR 1.261; 95% CI: 1.025, 1.551) and less anxious (OR: 0.846; 95% CI: 0.719, 0.996) about disasters. Conclusion: The results suggest that encouraging facility staff to be more familiar with disaster preparedness and make firmer decisions to act in the event of a disaster can improve attitudes toward onsite attendance during disasters.

Despite the frequent use of both advanced airway management (AAM) and epinephrine during resuscitation, no studies have evaluated the optimal sequencing of these interventions in paediatric out-of-hospital cardiac arrest (OHCA). We therefore aimed to investigate the association between the sequence of AAM and epinephrine administration and outcomes in paediatric patients with OHCA with non-shockable rhythms. This retrospective observational study analysed data from a multicentre OHCA registry in Japan from 2014 to 2022. We included paediatric patients (aged <18 years) with non-shockable OHCA who received AAM (endotracheal intubation or supraglottic airway device placement) and/or epinephrine administration. The primary outcome was 1-month survival, and the secondary outcomes were 1-month favourable neurological outcome (defined as a paediatric cerebral performance category of 1-3) and the return of spontaneous circulation (ROSC). Inverse probability of treatment weighting (IPTW) was applied based on propensity scores to address imbalances in patient characteristics. Of the 952 paediatric patients with non-shockable OHCA (median age (IQR) 2 (0-14) years), 577 (61%) were male. Of these, 455 and 497 belonged to the AAM-first and epinephrine-first groups, respectively. After IPTW, all covariates were well balanced between the AAM-first and epinephrine-first groups (standardised mean difference ≤0.10). Compared with the epinephrine-first group, the AAM-first group showed similar 1-month survival (adjusted OR (aOR), 1.09; 95% CI 0.61 to 1.86), favourable neurological outcome at 1 month (aOR, 0.79; 95% CI 0.12 to 5.07) and ROSC (aOR, 0.98; 95% CI 0.72 to 1.35). The sequence of AAM and epinephrine administration was not associated with 1-month survival, favourable neurological outcome at 1 month or ROSC in paediatric patients with non-shockable OHCA.

Introduction: Frailty in older adults is a multidimensional condition that affects healthy life expectancy. Engagement in meaningful activities (MA) is thought to support healthy aging, but the specific relationship between satisfaction with MA and frailty remains underexplored. This study investigated the longitudinal association between satisfaction with MA and frailty (physical, social, and cognitive domains) in community-dwelling older adults. Method: A total of 231 community-dwelling older adults who completed a 2-year follow-up were analyzed. Frailty in each domain was assessed at baseline and at 1- and 2-years. Participants’ MA and satisfaction were obtained through face-to-face interviews. Mixed-effects logistic regression models were used to examine the longitudinal associations between satisfaction with MA and frailty status trajectories. Results: At follow-up, changes in physical frailty status were observed in most participants. Robust status was commonly maintained in the social and cognitive frailty domain. Participants’ MA primarily involved leisure, sports, and domestic activities. Mixed-effects logistic regression analysis showed that satisfaction with MA was significantly associated with physical frailty, even after adjusting for potential covariates (odds ratio 0.68; 95% confidence interval 0.45, 0.99, p = 0.045). However, this association was not significant for social or cognitive frailty. Conclusion: Satisfaction with MA was longitudinally associated with physical frailty, but not with social or cognitive frailty.

Bridge inspections typically involve complex measurement criteria and take a long time. This study proposes a simpler inspection method that assesses the performance of reinforced concrete bridge girder beams. The method relies on crack length correlation with beam performance using theoretical approaches, Finite Element Model (FEM) simulations, and experimental testing. A reinforced concrete beam model is used to simulate similar flexural behavior to that of actual bridge girders. The results show that cracks form when concrete stress exceeds rupture stress, usually at 8%-12% of the ultimate capacity. Cracks grow until the steel reinforcement yields, which happens around 80%-90% of the ultimate capacity. Experimental crack length data at ultimate capacity align closely with FEM simulations, with a ratio of 0.92. In contrast, the results differ significantly from the theoretical predictions, with a ratio of 1.54. The study introduces six performance levels for reinforced concrete beams, linking crack length to beam performance. These parameters will help estimate bridge girder performance through visual crack assessments.

Children are vulnerable to exposure to airborne microplastics (MPs) because of their developing lungs and prolonged time spent indoors. Therefore, this study employed a computational fluid–particle dynamics framework to simulate the posture-dependent transport and deposition of MPs in a realistic airway model of a 2-year-old child extending to the 8th bronchial generation. A steady inhalation breathing flow rate of 5 L/min was used for both postures. Subsequently, a discrete-phase model was used to predict the transportation and deposition of MPs, which employed an appropriate drag coefficient model. MP configurations were selected from the field survey, identifying the diameters of 4.785, 9.797, and 15.731 µm with aspect ratios of 3, 5, and 10. The results showed that posture significantly altered the deposition patterns of small- and low-aspect-ratio MPs. Specifically, the total deposition fraction was higher in the upright position than in the supine position. Local deposition analyses revealed that hotspots of deposited MPs varied across the airways under the effects of posture, especially in the upper respiratory tract. These findings provide mechanistic insights into how posture shapes regional fiber deposition in children and highlight the need to consider body orientation in pediatric inhalation exposure assessments.

ABSTRACT Multiple myeloma (MM) is a malignant plasma cell disorder that primarily presents with CRAB symptoms (calcium elevation, renal failure, anemia, and bone abnormalities). In rare cases, MM manifests with systemic complications like skin ulcers, which present management challenges. Here, we report a 78‐year‐old Japanese man with MM and refractory severe skin ulcers. Despite the absence of CRAB symptoms, the patient developed painful, necrotic ulcers on his lower extremities. Initial treatment with antibiotics and prednisolone provided no improvement. Pathological findings indicated venous congestion and vasculopathy due to microthrombosis associated with hypergammaglobulinemia. Plasma exchange (PE) was performed to reduce M‐protein levels, leading to granulation and partial healing. However, ulcers recurred after PE cessation. Two years post‐diagnosis, symptomatic MM with anemia necessitated chemotherapy. Given the patient's advanced age and high infection risk, lenalidomide‐dexamethasone (Ld) therapy was initiated. This approach achieved complete epithelialization within 1 year, with no ulcer recurrence. Over 5 years, maintenance Ld therapy maintained low serum immunoglobulin G levels without systemic side effects or further relapses. This case highlights the utility of PE for temporary symptom relief and Ld therapy for long‐term management of MM‐associated skin ulcers. While the exact etiology of ulcers in this case remains unclear, elevated M‐protein levels and microthrombosis likely contributed. This case emphasizes the importance of individualized treatment strategies in MM patients with non‐CRAB complications like skin ulcers. Ld therapy alone may be a viable option for elderly MM patients with severe ulcers, even in the absence of CRAB symptoms. Further research is warranted to clarify ulcer pathophysiology and optimize treatment.