A plasma-near-passage unipolar aerosol charger (PNP charger) was developed for high-efficiency charging of sub-10 nm particles, and for the first time, an extrinsic charging efficiency eta(extr)>0.7 was demonstrated for 10 nm particles. The key feature of this device is that particles are passed for a very short time through the high ion concentration region near the plasma , enabling a large nt-product (n is the ion concentration, t is the residence time in the charging region) while minimizing t as much as possible. Analysis based on diffusion charging theory suggested that, at 3.0 L/min, the aerosol particles were exposed to a very high effective, path-averaged ion concentration of 1.1 & times;10(16) m(-3) for only 4.2 ms. This approach reduced diffusion loss of sub-10 nm particles and enabled highly efficient charging. Furthermore, the charged particle generation rate was the highest among previous studies for all particles below 10 nm. These results have the potential to reduce material loss and improve production throughput in device fabrication processes utilizing aerosol particles.
Improving the visibility of lung nodules, which are often hidden by bone shadows and difficult to identify, mains a challenge in chest radiography. This study aims to develop an algorithm for generating novel bone suppressed images using photon-counting techniques. The core idea of our algorithm is to fit photon interaction cross-sections to X-ray attenuation data measured with photon-counting detectors. Based on further calculations using the derived fitting coefficients, both density (rho) and amount-of-substance concentration (mol) were determined. The product of these values produced a rho & times; mol image exhibiting a clear bone-suppression effect. We conducted a virtual chest imaging simulation using 10 patient datasets acquired via clinical photon-counting computed tomography (PC-CT). The CT images were converted into rho & times; mol images following the proposed processing procedure, and two-dimensional chest images were generated through projection. Quantitative evaluations confirmed that the proposed images achieved sufficient bone suppression. Furthermore, commercial software provided by a vendor was used to generate bone-suppressed images from conventional images projected from CT data. A comparable bone-suppression effect on the ribs was observed between the vendor-generated images and our proposed images, while lesion visibility (e.g., lung nodules) was preserved. Additionally, bone-suppression effects in our images were observed in the vertebrae and clavicles located outside the lung fields. Our research demonstrates the value of constructing general X-ray imaging systems using photon detectors.
X-ray imaging using photon-counting detectors (PCDs) allows for the calculation of quantitative images such as the effective atomic number (Zeff). However, physical phenomena such as characteristic X-ray emission and charge sharing can cause incomplete total absorption events during signal generation, which reduces the accuracy of X-ray penetration analysis. To solve the problem, an anti-coincidence mode (ACM) has been developed, but complete correction has not been established. We aimed to investigate the accuracy of Zeff image when the proposed software-based corrections, namely beam hardening and response function corrections, are added to the hardware-based correction of the ACM. The response function was calculated using the Monte-Carlo simulation code. In a simulation study, we analyzed a phantom composed of virtual materials with Zeff values of 4–16. While sufficient accuracy cannot be achieved by applying only the ACM, it was demonstrated that low-noise Zeff images can be obtained by applying our correction. Furthermore, it was demonstrated that Zeff images of food samples can be generated by using actual non-destructive testing equipment with a 10 m/min transportation speed. In conclusion, our correction procedure can maximize the performance of PCDs, and our findings are essential for promoting imaging techniques concerning quantitative images.
This study investigates the behavioural and operational dynamics of a night-time demand-responsive transport (DRT) system in the alpine resort of Hakuba, Japan, within a digitally mediated service environment, with particular attention to the temporal and spatial patterns of seasonal tourism. Using a dataset of 5,232 completed trips, the analysis identifies the key drivers of demand intensity in a low-density mountainous context. The findings reveal a dispersed hub configuration, defined here as notable demand concentration at a limited number of functional stops combined with low geographic clustering and scattered local hotspots. This pattern reflects the role of DRT in connecting physically fragmented activity nodes. Moreover, the results highlight a distinct seasonal tourism rhythm: demand is shaped by month-to-month variation within the winter season and shortterm temporal persistence, rather than conventional weekday-weekend cycles. The scale of passenger-carrying service delivery provides a baseline for understanding the operational demands of night-time DRT in rural, seasonally intensive tourism settings. The findings from the study suggest that DRT planning in such contexts should move beyond rigid, calendar-based approaches towards seasonally adaptive strategies that account for temporal persistence and spatial fragmentation in tourism-driven mobility systems.
Objectives: Adult ICU patients receiving invasive mechanical ventilation (IMV) are at risk of pressure injury (PI) and medical device-related pressure injury (MDRPI) due to immobility, impaired perfusion, and device contact. This scoping review synthesized evidence on PI and MDRPI risk factors and preventive strategies. Methods: This scoping review followed the Arksey and O'Malley framework and PRISMA-ScR guidelines. Five databases (PubMed, CINAHL, Scopus, MEDLINE, ScienceDirect) were searched from inception to April 2026. Studies of adult ICU patients receiving IMV reporting PI, MDRPI, risk factors, or preventive strategies were eligible. Results: Forty-two studies from 14 countries (2009-2026) were included. PI incidence ranged from 10.3 to 36.3% (up to 88.7% when prone-positioned); MDRPI (oral mucosal injury) ranged from 25.9 to 43.1% (80.1% with a broader erythema criterion). Cutaneous PI mainly affected the sacrum, heels, occiput, face, and thorax (generally Stage 1-2); oral mucosal MDRPI, assessed using heterogeneous severity criteria, was typically mild-to-moderate. Onset was commonly reported on days 3-9. PI risk factors included immobility, impaired perfusion, vasopressor therapy, and poor nutrition; MDRPI risk factors involved prolonged intubation and device exposure. Preventive strategies included device repositioning, securement adjustment, device-contact protection, and oral care. Conclusions: Prolonged mechanical loading and reduced tissue tolerance are intensified by immobility, sedation, hemodynamic instability, impaired perfusion, vasopressor use, and device exposure. Early-stage cutaneous PI and mild-to-moderate mucosal MDRPI were more commonly reported than severe cutaneous and mucosal injuries; given the descriptive, non-comparative evidence, this cannot be attributed to preventive effectiveness. Early monitoring may be important for detecting early-stage injury and identifying progression toward more severe injury. Implications for clinical practice: Prevention should combine pressure redistribution with tolerance-based repositioning, skin monitoring, device securement, device-contact protection, and oral mucosal care. An exploratory, hypothesis-generating observation is that the first 10 days of ICU stay may be a high-risk period, requiring prospective validation.
