Tag: pubmed

Chaos. 2026 Aug 1;36(8):083149. doi: 10.1063/5.0332883.

ABSTRACT

The dynamic model that couples micro- and macro-level factors holds significant importance for studying diseases with long incubation periods, which also presents a major challenge in multiscale modeling. Based on the nested models, we propose a multiscale model with bidirectional coupling between population-level transmission and within-host viral progression, by including the feedback from the population scale to the individual scale mediated by perceived disease-induced mortality and its effect on treatment adherence. Suppose a saturating incidence and a linear mortality law, we rigorously analyze the dynamics of the proposed system and reveal multiple endemic equilibria and local bifurcations (backward, fold, and Hopf). Numerical continuation further identifies codimension-two organizing centers (Bogdanov-Takens points) and global bifurcations, including homoclinic bifurcations and fold bifurcations of limit cycles. These give rise to parameter regions exhibiting two distinct forms of bistability: the coexistence of two equilibria and the coexistence of an equilibrium with a stable periodic orbit. By contrast, a corresponding unidirectional model exhibits comparatively simple dynamics and predicts that sufficiently high drug efficacy alone will achieve elimination. The bidirectional model, however, yields richer asymptotical and transient behavior and indicates that population-level eradication generally requires simultaneous, substantial improvements in both drug efficacy and medication adherence. These findings show that the multiscale model with bidirectional coupling can change epidemic outcomes and produce more realistic predictions for control of chronic infections.

PMID:42640183 | DOI:10.1063/5.0332883

Chaos. 2026 Aug 1;36(8):083150. doi: 10.1063/5.0340300.

ABSTRACT

We investigate how stochastic Poisson impulsive forcing influences the spatiotemporal dynamics of a two-dimensional network of Hindmarsh-Rose neurons. Unlike continuous noise, impulsive forcing introduces discrete, state-dependent perturbations, making the system response highly sensitive to both the statistics and the spatial structure of the input. In most of the parameter space, stochastic impulses destabilize the initial coherent spiral-wave regime and lead to unstable spiral-wave activity. At the same time, they can also produce constructive effects. Both spatially uniform and spatially non-uniform forcing induce stable target waves that are absent in the autonomous system, suggesting a common mechanism of structure formation driven by discrete excitation events. In addition, spatially uniform forcing suppresses spatial heterogeneity and leads to coherent, nearly synchronous oscillations, demonstrating that even random impulses can promote global synchronization. By contrast, spatially uncorrelated forcing enhances front fragmentation and incoherence, especially at higher amplitudes. To identify and compare the resulting regimes in a highly multistable parameter space, we use a feature-based clustering approach based on statistical descriptors of wave morphology and evolution across multiple time scales. This results in a clear separation of physically distinct regimes. Overall, stochastic Poisson impulses serve not only as a source of disorder but also as an effective control mechanism for destabilizing, reorganizing, and synchronizing collective wave dynamics in networks of coupled neuronal oscillators.

PMID:42640182 | DOI:10.1063/5.0340300

Ir Med J. 2026 Aug 20;119(7):126.

ABSTRACT

AIMS: To evaluate whether school-located influenza vaccination (SLIV) improves uptake and to assess parental attitudes in two primary schools.

METHODS: A post-season questionnaire was distributed to parents following GP-led SLIV clinics in 2024/25 assessing uptake, reasons for non-vaccination and attitudes using 5-point Likert scales and free-text responses. 66 of 67 responses (98.5%) were analysed.

RESULTS: The survey was issued to 201 eligible schoolchildren across two rural primary schools. There were 66 responses (33%). Of respondents, 32 (48.5%) children were vaccinated; 22 (33%) in school and 10 (15%) elsewhere. Parents rated clarity of information regarding vaccination highly, with 52 (80%) reporting information received as clear or very clear. Parents were more likely to vaccinate when SLIV was available, with 34 (52%) reporting that they were likely or very likely to vaccinate, rising to 29 (91%) among those vaccinated this year. The most common reasons for declining were belief the vaccine was unnecessary (21/34, 62%) and safety concerns (9/34, 26%).

DISCUSSION: SLIV improved uptake relative to national and local averages and was generally well received. Attitudinal barriers, especially perceptions of low necessity and safety concerns, remain the primary obstacles. Expanding SLIV alongside stronger public health messaging may offer a scalable strategy to increase uptake.

PMID:42640173

Pain Res Manag. 2026;2026(1):e6203306. doi: 10.1155/prm/6203306.

ABSTRACT

BACKGROUND: Low back pain (LBP) is one of the most prevalent pain conditions worldwide and a major contributor to disability. Although numerous epidemiological studies have investigated LBP, heterogeneity in pain definitions and assessment indicators has limited comparability across studies. A brief and reproducible questionnaire incorporating core LBP indicators commonly used in pain epidemiology may facilitate consistent assessment of LBP occurrence and impact in population-based research.

METHODS: We proposed a brief low back pain questionnaire (B-LBPQ) designed to assess the occurrence and characteristics of LBP in epidemiological studies. The B-LBPQ consists of seven items covering current LBP, LBP during the past 12 months, lifetime experience of LBP, pain duration, and pain-related interference with daily activities. A cross-sectional validation study was conducted among 783 Japanese welfare workers aged 20-74 years (mean age: 41.9 years) undergoing routine health checkups. Construct validity was examined by comparing questionnaire-based LBP classifications with scores on the Roland-Morris Disability Questionnaire (RDQ). Internal consistency was assessed using Cronbach’s alpha. Test-retest reliability over a 2-week interval was evaluated among 595 participants using kappa statistics, prevalence-adjusted bias-adjusted kappa (PABAK), and weighted kappa coefficients.

RESULTS: Construct validity was supported by significantly higher RDQ scores among participants reporting LBP compared with those without LBP (all p < 0.001). For items with multiple response categories, significant differences and ordered trends in RDQ scores were observed across response categories (all p for trend < 0.001). Internal consistency was acceptable (Cronbach’s α = 0.87). Test-retest reliability ranged from substantial to almost perfect, with PABAK values of 0.70-0.85 for dichotomous items and weighted kappa coefficients of 0.65-0.81 for items with three or more categories.

CONCLUSIONS: The B-LBPQ demonstrated initial reliability and construct validity in Japanese welfare workers and may be useful for epidemiological assessment of LBP. However, further validation in diverse populations and settings is required.

PMID:42638610 | DOI:10.1155/prm/6203306

Anaesthesiol Intensive Ther. 2026 Aug 17;58(1):172-178. doi: 10.5114/ait/226447.

ABSTRACT

BACKGROUND: Quantitative neuromuscular monitoring is essential for the safe management of neuromuscular blockade. Although electromyography (EMG) is increasingly regarded as a reference technique, kinemyography (KMG) remains widely used in clinical practice; however, clinically relevant differences between these modalities during onset and recovery of neuromuscular blockade are not fully understood.

METHODS: In this prospective observational study, adult patients undergoing general anaesthesia with non-depolarising neuromuscular blocking agents were simultaneously monitored using EMG and KMG applied to opposite hands, and onset and recovery times of neuromuscular block were compared between modalities; additionally, a novel EMG-derived parameter (T1%) was explored as a marker of recovery.

RESULTS: In the 137 analysed patients, EMG and KMG differed during onset and recovery, with greater and only statistically significant disagreement during onset (EMG 158 ± 74 s vs. KMG 118 ± 68 s, P < 0.001; recovery: EMG 27 ± 22 min vs. KMG 24 ± 21 min, P = 0.242). T1% tended to be higher with sugammadex than with spontaneous recovery (P = 0.074).

CONCLUSIONS: KMG and EMG are not interchangeable for perioperative neuromuscular monitoring; the observed disagreement suggests that KMG may overestimate neuromuscular block, whereas EMG-based monitoring may provide a safer approach. The EMG-derived parameter T1% appears promising but requires further validation before routine clinical use.

PMID:42638596 | DOI:10.5114/ait/226447

Med Decis Making. 2026 Aug 25:272989X261472806. doi: 10.1177/0272989X261472806. Online ahead of print.

ABSTRACT

INTRODUCTION: Cost-effectiveness modelling often requires the extrapolation of survival data from clinical trials. The choice of extrapolation method is often uncertain and can have a profound effect on the results. We propose an approach that incorporates external evidence (eg, from published studies, registries, or elicited clinical opinion) into the extrapolation process to reduce uncertainty. This method can be applied to adjust previously fitted parametric curves as a secondary analysis, without access to the underlying patient-level data. Adjusted curves can be easily exported and used in spreadsheet-based models.

METHODS: Standard parametric survival curves are fitted to time-to-event data using maximum likelihood estimation (MLE). These are combined with external evidence on expected cohort-level survival at a future time point(s), formulated as a probability distribution, to generate adjusted survival curves that simultaneously incorporate both observed data and external evidence. Parameter estimation uses importance sampling and multivariate normal approximations of the likelihood. We apply our method to a case study of survival extrapolation from immuno-oncology.

RESULTS: Our method resulted in extrapolated survival predictions that were more closely aligned with the external evidence compared with the standard (MLE-based) approach. The incorporation of external evidence decreased the between-distribution variance (reduced structural uncertainty) and for most distributions also decreased within-distribution variance (reduced parametric uncertainty).

CONCLUSION: Our extrapolation method can reduce uncertainty when valid external evidence is available. Only MLE-based parameter estimates are required to implement our method; thus, secondary model users such as health technology assessment bodies can adjust survival extrapolations from existing cost-effectiveness models without access to patient-level data. Implementation is straightforward and computationally efficient, and outputs are easily incorporated into existing cost-effectiveness models.

PMID:42638584 | DOI:10.1177/0272989X261472806

Anesth Pain Med (Seoul). 2026 Aug 21. doi: 10.17085/apm.25462. Online ahead of print.

ABSTRACT

BACKGROUND: Effective postoperative analgesia is essential for optimizing recovery and patient satisfaction after inguinal hernia surgery. Therefore, we compared transdermal buprenorphine and fentanyl patches with conventional analgesia for pain control and quality of recovery-15 (QoR-15).

METHODS: In this prospective, randomized study 150 patients classified as American Society of Anesthesiologists (ASA) I-III scheduled for elective open inguinal hernia repair were randomized into three groups; (n=50 each) Group B (buprenorphine 10 µg/h patch), Group F (fentanyl 25 µg/h patch), and Group C (intravenous paracetamol and tramadol). Patches were applied 12 h preoperatively. The primary outcome was visual analog scale (VAS) pain score, assessed at 1, 6, 12, and 24 h. Secondary outcomes included QoR‑15 scores and rescue‑analgesic requirements. Statistical analysis was performed using the Kruskal-Wallis and Mann-Whitney U tests with Bonferroni correction.

RESULTS: Baseline demographic characteristics and perioperative hemodynamic parameters were comparable across groups. Median postoperative VAS scores at 6, 12, and 24 h were significantly lower in both transdermal groups than in the control group. QoR-15 scores at 24 h were 124 (122-125) (C), 127 (125-129) (F), and 133 (131-134) (B), at 48 h were 129 (128-130), 136 (134-138), and 137 (135-139) for Groups C, F, and B, respectively (P = 0.001).

CONCLUSIONS: Transdermal buprenorphine and fentanyl provided effective postoperative analgesia and were associated with improved quality of recovery compared with standard analgesia. Buprenorphine showed a significant advantage over fentanyl in QoR-15 at 24 h, however, this difference was not significant at 48 h.

PMID:42638571 | DOI:10.17085/apm.25462

J Appl Clin Med Phys. 2026 Sep;27(9):e70757. doi: 10.1002/acm2.70757.

ABSTRACT

BACKGROUND: Accurate contouring of target volumes and organs at risk is critical in radiotherapy. While deep learning (DL) models offer automated contouring, their clinical applicability to real-world cases containing anatomical variations and artifacts requires rigorous validation.

PURPOSE: To evaluate the clinical accuracy and potential vulnerabilities of RatoGuide, novel DL-based auto-segmentation software, using a dataset including atypical cases derived from routine clinical practice.

METHODS: This single-center retrospective study included 69 thoracic and male pelvic cases. The cohort was intentionally selected to encompass diverse anatomies and artifacts (e.g., pacemakers, SpaceOAR implants, artificial femoral head replacements, and unilateral atelectasis). Auto-contours generated by RatoGuide were compared with expert-approved manual contours. Performance was evaluated quantitatively using the Dice Similarity Coefficient (DSC) and 95th percentile Hausdorff Distance (HD95), and qualitatively via a 5-point visual assessment scale by four independent reviewers. Statistical comparisons between cohorts were performed using the Mann-Whitney U test. Additionally, a dosimetric evaluation was conducted for male pelvic cases to assess clinical impact.

RESULTS: In typical cases, the software maintained high segmentation accuracy (thorax: mean DSC 0.856, mean HD95 6.89 mm; male pelvis: mean DSC 0.874, mean HD95 4.11 mm). However, performance declined in atypical cohorts (thorax: mean DSC 0.808, p = 0.0457, mean HD95 12.22 mm, p = 0.0002; male pelvis: mean DSC 0.828, p = 0.1620, mean HD95 6.16 mm, p = 0.0075). Notable decreases in accuracy were observed in challenging scenarios, such as artificial femoral head replacements (DSC: 0.754) and unilateral atelectasis (DSC: 0.784). Qualitative assessment revealed that errors were primarily due to anatomical factors and artifacts. Furthermore, the dosimetric evaluation identified one critical false-negative error where a dose constraint violation was overlooked when the DL contour was used.

CONCLUSIONS: RatoGuide demonstrated favorable performance in typical cases, but accuracy declined in atypical cases with artifacts or altered anatomy. For clinical implementation, rigorous visual verification and manual review by experts are essential, particularly for atypical cases and organs in high-dose gradient regions.

PMID:42638554 | DOI:10.1002/acm2.70757

J Appl Clin Med Phys. 2026 Sep;27(9):e70765. doi: 10.1002/acm2.70765.

ABSTRACT

BACKGROUND: There is an increasing use of magnetic resonance imaging (MRI) for segmentation of target volumes and organs at risk due to superior soft tissue contrast compared to computed tomography (CT). Conventional workflows require CT-MRI registration, introducing geometric uncertainty that can propagate to dose delivery. MRI-only radiotherapy, based on AI-generated synthetic CT (sCT) and segmentations from T2-weighted images, offers a single-modality approach, potentially eliminating registration errors.

PURPOSE: Our study aims to evaluate whether an MRI-only workflow, using commercial AI models for segmentation and sCT generation (MVision), demonstrates performance comparable to expert-defined segmentations and reference CT-based calculations within the studied dataset.

METHODS: We analyzed five segmentations on 19 male pelvis patients from the Gold Atlas dataset, providing deformably co-registered CT and MRI, sCTs, with multi-observer and consensus segmentations. We investigated segmentation accuracy, image similarity, and evaluated the dosimetric impact by comparing AI- to manual segmentations and CTs to sCTs. Wilcoxon signed-rank tests were used for statistical significance and leave-one-out kappa determined segmentation outliers.

RESULTS: Results show that AI-segmentations achieved accuracy comparable to interobserver variability across all organs. Median Dice coefficients exceeded 0.9 for the prostate and bladder, and distance metrics closely matched the manual results. The leave-one-out kappa showed that AI-segmentations were indistinguishable from manual observers for all organs. sCTs showed high similarity to the reference CTs, with a median mean absolute error of 34.0 HU and median structural similarity index of 0.93. Dose recalculations showed excellent agreement; median 3D-gamma pass rate was 99.8% (2%/2 mm), and mean absolute dose difference was 0.036 Gy. All evaluated clinical dose constraints remained fulfilled after recalculation on the sCT.

CONCLUSIONS: Our results confirm that an AI-segmentation and MRI-sCT workflow provides geometric, image, and dose accuracy comparable to manual- and CT-based references, supporting their integration into clinical workflows for pelvic radiotherapy.

PMID:42638512 | DOI:10.1002/acm2.70765

J Hum Lact. 2026 Aug 25:8903344261475026. doi: 10.1177/08903344261475026. Online ahead of print.

ABSTRACT

BACKGROUND: Breastfeeding intent and practices have not been well explicated in women of color, who are likely to experience perinatal anxiety, depression, or stress.

RESEARCH AIM: The aim of this study was to examine factors influencing intent and infant feeding practices in pregnant people of color with heightened mental health conditions through 6 months postpartum.

METHOD: As part of a larger longitudinal randomized control trial, 154 Black and/or Hispanic pregnant participants reported infant feeding intent at approximately 31 weeks’ gestation, and feeding practices at 6 weeks and 6 months postpartum. Hierarchical logistic regression models examined sociodemographic characteristics, Baby-Friendly designation, and antenatal mental health symptoms as predictors of breastfeeding at 6 weeks and 6 months postpartum.

RESULTS: In this study, compared to national statistics, intent to breastfeed and initiation rates respectively, were higher in Hispanic women (96.9% and 90.6%) than in Black women (91.1% and 94.1%). In multivariable models (n = 147), maternal age was positively associated with breastfeeding at 6 weeks (aOR ≈ 1.10 per year). Delivery in a Baby-Friendly site was independently associated with higher odds of breastfeeding (aOR = 2.74-2.83 across models). Anxiety, depressive, and stress symptoms did not meaningfully attenuate this association, and none were independently associated with breastfeeding.

CONCLUSION: With supportive breastfeeding practices, women can successfully initiate breastfeeding. Mothers experiencing increased anxiety, depression, or stress, breastfed, irrespective of their mental health. Nonetheless, breastfeeding decreased over time. Further research on community resources that can continue to support vulnerable women in their breastfeeding practices is needed.

PMID:42638469 | DOI:10.1177/08903344261475026