The radiation tolerance of several inorganic scintillators was investigated to ensure their reproducibility in electron beam exposure. LuAG:Pr, GPS:Ce, LYSO:Ce, GAGG:Ce single, and GAGG:Ce ceramic scintillators were p...
The radiation tolerance of several inorganic scintillators was investigated to ensure their reproducibility in electron beam exposure. LuAG:Pr, GPS:Ce, LYSO:Ce, GAGG:Ce single, and GAGG:Ce ceramic scintillators were prepared with all faces polished mechanically and thermally annealed. Electron beam exposures at 50, 100, 500, 1000, and 3000 Gy were conducted using a 6 MeV clinical electron beam from a Varian Novalis Tx linear accelerator with a 270-degree bending magnet. Energy spectra were acquired by exciting a 137 Cs source coupled to a photomultiplier tube (PMT) kept in the dark box with a biased high voltage of -900 V. The relative light output of GPS:Ce and LuAG:Pr compared to the baseline decreased steadily after electron beam exposure, recording 66.2% and 56.9%, respectively, at a dose of 3 kGy. The transmittance and photoluminescence of these scintillators also deteriorated with increasing crystallographic defects. In contrast, LYSO:Ce and GAGG:Ce scintillators demonstrated high tolerance to electron beams. Thermal annealing was shown to restore the scintillation properties of the degraded scintillators. These findings provide valuable insights into the radiation tolerance of inorganic scintillators and have implications for the design of radiation detectors for various applications, including radiation therapy and aerospace. Using inorganic scintillators in radiation therapy is particularly critical for estimating radiation exposure. The potential of these scintillators in aerospace applications will also be explored based on the promising results of this study.
The major cause of recurrence after pulmonary vein (PV) isolation for atrial fibrillation (AF) is PV reconnection, and thicker wall could be associated with reconnection. This study aimed to evaluate the wall thicknes...
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The major cause of recurrence after pulmonary vein (PV) isolation for atrial fibrillation (AF) is PV reconnection, and thicker wall could be associated with reconnection. This study aimed to evaluate the wall thickness of the PV antrum in reconnection sites using a three-dimensional (3D) wall thickness map. A total of 91 patients who underwent a second ablation procedure due to AF recurrence were evaluated. The locations of the PV reconnection sites were confirmed in electroanatomical maps. A 3D atrial wall thickness (AWT) map was created using computed tomography scan data. The AWT values of the ablation lines of the index procedure were graded in each segment of the PV antrum: grade 1, 0.5 < AWT ≤ 1.0 mm; grade 2, 1.0 < AWT ≤ 1.5 mm; grade 3, 1.5 < AWT ≤ 2.0 mm; grade 4, 2.0 < AWT ≤ 2.5 mm; grade 5, AWT > 2.5 mm. A total of 281 PV reconnection sites among 1256 segments of the PV antrum in 79 patients were detected. The average AWT grades were 2.7 ± 1.0 and 2.2 ± 1.0 in the reconnected and non-reconnected segments, respectively (P < 0.01). Higher AWT grades were observed in the reconnected superior segments of the left superior PV, carina and inferior segments of the left inferior PV, superior and posterior segments of the right superior PV, and posterior and inferior segments of the right inferior PV. The reconnected segments of the PV antrum showed thicker myocardium than the non-reconnected ones in patients with recurrent AF after catheter ablation. A wall thickness map for PV isolation could be considered for customized ablation in order to reduce PV reconnection.
Wall shear stress (WSS) has been associated with development of high-risk plaque, which increases the likelihood for major adverse cardiac events. Recently, we have used a catheter-based, 3D intravascular forward-view...
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ISBN:
(数字)9781728154480
ISBN:
(纸本)9781728154497
Wall shear stress (WSS) has been associated with development of high-risk plaque, which increases the likelihood for major adverse cardiac events. Recently, we have used a catheter-based, 3D intravascular forward-viewing ultrasound (FV US) transducer to directly estimate velocity fields in the femoral artery of a pig. Because inserting a catheter will affect the blood flow dynamics in the artery, in this work, the effects of a catheter on flow dynamics are experimentally quantified in both femoral and coronary stenotic vessels in phantoms to determine conditions in which velocity can be accurately estimated. An external linear array transducer was used to estimate velocity in the lumen at 5000 fps via a particle imaging velocimetry approach. The current study indicates that a hollow, catheter-based FV US could be used to quantify the flow dynamics surrounding stenoses with minimal flow disturbance, and thus could potentially assess elevated WSS and risk of plaque rupture.
Electronic health record (EHR) foundation models have been an area ripe for exploration with their improved performance in various medical tasks. Despite the rapid advances, there exists a fundamental limitation: Proc...
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The human brain choroid plexus (ChP) is a highly organized secretory tissue with a complex vascular system and epithelial layers in the ventricles of the brain. The ChP is the body’s principal source of cerebrospinal...
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In this study, we established a 3D in vitro model of human lymphatic vessel (LV) within tumor immune microenvironment (TIME) using an injection-molded plastic array culture platform. Our platform enabled robust and re...
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The feedback between mechanical and chemical signals plays a key role in controlling many biological processes and collective cell behavior. Here we focus on the emergence of spatiotemporal density waves in a one-dime...
The feedback between mechanical and chemical signals plays a key role in controlling many biological processes and collective cell behavior. Here we focus on the emergence of spatiotemporal density waves in a one-dimensional “cell train.” Combining a minimal theoretical model with in vitro experiments on MDCK epithelial cells confined to a linear pattern, we examine the spontaneous oscillations driven by feedback between myosin activation and mechanical deformations, as well as their effect on the response of the tissue to externally applied deformations. We show that the nature and frequency of spontaneous oscillations is controlled by the size of the cell train, with a transition from size-dependent standing waves to intrinsic spontaneous waves at the natural frequency of the tissue. The response to external boundary perturbations exhibits a resonance at this natural frequency, providing a possible venue for inferring the mechanochemical couplings that control the tissue behavior from rheological experiments.
Sargassum horneri (S. horneri) is an edible species of large brown algae inhabiting along the coasts of northeastern Asia. The study focuses on the impact of celluclast enzyme extract of S. hoeneri (SHC) on various im...
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Soft robots, capable of safe interaction with delicate objects through their flexibility and compliance, are attracting attention in various real-world applications as manipulators, biomedical devices and wearable too...
Soft robots, capable of safe interaction with delicate objects through their flexibility and compliance, are attracting attention in various real-world applications as manipulators, biomedical devices and wearable tools. As these technologies advance, the ability to perform complex tasks in a robust and reliable way becomes essential. Thus, the incorporation of embedded intelligence in soft robots, which enables them to perceive external environments and generate appropriate actions, is increasingly important. Inspiration from sophisticated biological systems, which exhibit optimized behaviours through the acquisition of external information, promotes the development of intelligent soft robots. Here, we introduce biomimicry strategies for intelligent soft robotics and highlight progress in how soft robots interact with their environment and perform tasks. First, we discuss sensors inspired by the sensory nervous systems and soft actuators inspired by the musculoskeletal systems. Furthermore, we investigate various applications such as manipulation, exploration, wearable devices, biomedical devices and imperceptible devices. We conclude discussing the challenges and offering a perspective on the future direction of this field.
In regenerative medicine, effective management of tissue ischemia in surgical skin flaps is crucial, yet challenging, particularly because inadequate blood flow often leads to necrosis at the distal flap tips. This st...
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In regenerative medicine, effective management of tissue ischemia in surgical skin flaps is crucial, yet challenging, particularly because inadequate blood flow often leads to necrosis at the distal flap tips. This study aimed to examine the therapeutic potential of catalase-coated oxygen-generating microparticles embedded in gelatin methacryloyl (cOMP-GelMA) hydrogel to establish an optimized environment conducive to tissue regeneration. Using a large 3 × 9 cm 2 rat random-pattern skin flap model, flap survival and regeneration were evaluated across four groups: control, pure GelMA hydrogel, and cOMP-GelMA hydrogel with two concentrations of cOMPs (0.2 % and 0.5 % w/v). These findings revealed that cOMP-GelMA comprising 0.2 % OMP significantly enhanced angiogenesis, arteriogenesis, mitochondrial biogenesis, and antioxidant capacity compared to 0.5 % cOMP-GelMA. Furthermore, the alleviation of the inflammatory response was more pronounced at lower cOMP concentrations than at higher concentrations. These results demonstrate that mild hypoxia, facilitated by moderate oxygen delivery, is beneficial for tissue repair and regeneration through peroxisome proliferator-activated receptor gamma coactivator 1-alpha- and hypoxia-inducible factor 1-alpha-dependent signaling pathways. This study highlights the innovative aspect of using a large-scale model to explore the therapeutic benefits of mild hypoxia and suggests that controlled oxygen delivery by cOMPs can improve the long-term functional recovery of ischemic tissues.
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