17 research outputs found

    Fast-MC-PET: A Novel Deep Learning-aided Motion Correction and Reconstruction Framework for Accelerated PET

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    Patient motion during PET is inevitable. Its long acquisition time not only increases the motion and the associated artifacts but also the patient's discomfort, thus PET acceleration is desirable. However, accelerating PET acquisition will result in reconstructed images with low SNR, and the image quality will still be degraded by motion-induced artifacts. Most of the previous PET motion correction methods are motion type specific that require motion modeling, thus may fail when multiple types of motion present together. Also, those methods are customized for standard long acquisition and could not be directly applied to accelerated PET. To this end, modeling-free universal motion correction reconstruction for accelerated PET is still highly under-explored. In this work, we propose a novel deep learning-aided motion correction and reconstruction framework for accelerated PET, called Fast-MC-PET. Our framework consists of a universal motion correction (UMC) and a short-to-long acquisition reconstruction (SL-Reon) module. The UMC enables modeling-free motion correction by estimating quasi-continuous motion from ultra-short frame reconstructions and using this information for motion-compensated reconstruction. Then, the SL-Recon converts the accelerated UMC image with low counts to a high-quality image with high counts for our final reconstruction output. Our experimental results on human studies show that our Fast-MC-PET can enable 7-fold acceleration and use only 2 minutes acquisition to generate high-quality reconstruction images that outperform/match previous motion correction reconstruction methods using standard 15 minutes long acquisition data.Comment: Accepted at Information Processing in Medical Imaging (IPMI 2023

    Targeting suicidal ideation in major depressive disorder with MRI-navigated Stanford accelerated intelligent neuromodulation therapy

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    High suicide risk represents a serious problem in patients with major depressive disorder (MDD), yet treatment options that could safely and rapidly ameliorate suicidal ideation remain elusive. Here, we tested the feasibility and preliminary efficacy of the Stanford Accelerated Intelligent Neuromodulation Therapy (SAINT) in reducing suicidal ideation in patients with MDD. Thirty-two MDD patients with moderate to severe suicidal ideation participated in the current study. Suicidal ideation and depression symptoms were assessed before and after 5 days of open-label SAINT. The neural pathways supporting rapid-acting antidepressant and suicide prevention effects were identified with dynamic causal modelling based on resting-state functional magnetic resonance imaging. We found that 5 days of SAINT effectively alleviated suicidal ideation in patients with MDD with a high response rate of 65.63%. Moreover, the response rates achieved 78.13% and 90.63% with 2 weeks and 4 weeks after SAINT, respectively. In addition, we found that the suicide prevention effects of SAINT were associated with the effective connectivity involving the insula and hippocampus, while the antidepressant effects were related to connections of the subgenual anterior cingulate cortex (sgACC). These results show that SAINT is a rapid-acting and effective way to reduce suicidal ideation. Our findings further suggest that distinct neural mechanisms may contribute to the rapid-acting effects on the relief of suicidal ideation and depression, respectively

    Research on Energy Saving and Economy of Old Buildings Based on Parametric Design: A Case Study of a Hospital in Linyi City, Shandong Province

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    With the need for a green economy and the introduction of low-carbon policies, more and more old buildings are being transformed to improve the thermal performance of buildings and reduce energy consumption. However, people ignore the village buildings and the old public buildings. Based on the investigation of a typical health center in Linyi City, this paper proposed improvement measures using EnergyPlus simulation software and JePlus parameter chemical tools. The various factors analyze the various parts of the enclosure, and the energy-saving effect of the roof is better than that of the exterior wall: When the thickness of the insulation layer gradually increases from 0 cm to 30 cm, the unit energy consumption of the building gradually decreases from 57 kW·h/m2 to 42.8 kW·h/m2, while that of the roof is gradually reduced to 24.41 kW·h/m2. Double exterior windows effectively reduce the energy consumption of the building in all renovation schemes. The optimal scheme is selected through the parameterized design of all the overall enclosure reconstruction schemes and the initial investments. The results showed that the investment recovery of the selected scheme was between 1.36–5.28 years. Plan 5 (12 cm XPS is used as insulation material for the exterior wall and roof, and the exterior window is replaced with 6 mm medium transmittance Low-e + 12 mm air + 6 mm clear) had the highest energy efficiency (91.11%). Plan 2 (6 cm XPS is used as insulation material for the exterior wall and roof, and the exterior window is replaced with 12 mm single medium transmittance heat-reflecting glass) had the shortest investment recovery period (2.04 years)

    What Affects the Use Flexibility of Pocket Parks? Evidence from Nanjing, China

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    The use flexibility of pocket parks is one of the essential factors that determine their service compatibility, efficiency, and attraction for park users in densely populated cities. To examine the factors that affect the use flexibility of pocket parks, we collected data on the periodic use of 74 pocket parks through a field survey in Nanjing and adopted the Shannon Wiener diversity index to quantitatively measure this variable. After using a multiple regression model series, we examined the internal and surrounding factors that affect the use flexibility of pocket parks on weekdays and weekends, respectively, and compared them with those that affect the use intensity of pocket parks. The results showed that paved ground and the mixed use of surrounding land promoted both use flexibility and intensity of pocket parks. Boundary buildings and surrounding residents only promoted their use flexibility, while tree canopies and exercising facilities only promoted the use intensity of pocket parks. A significant correlation (p < 0.05) was also found between the use flexibility and intensity on weekdays. These findings can contribute to future decisions regarding pocket park planning and design in Nanjing and similar cities

    Multilevel Structural Characteristics of Jinshajiang Main Fault and Its Influence on Engineering

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    It is of great significance to study the geological characteristics of faults and the corresponding displacement patterns for the tunnel engineering crossing active faults. On the basis of field investigation and geological data analysis, it is found that the secondary weak structures, such as narrow cleavage bands, narrow joint bands, fault gouge zones, and small folds, often appear in the fault fracture zones and affected zones. The multilevel structure of fault is proposed from mechanics and engineering by summarizing their main characteristics. Taking the outcrop of fracture zones of Batang section, Jinshajiang main fault in the Qinghai-Tibet Plateau as the research object, the geometric characteristics of rock masses, the particle size, mineral composition, and mechanical characteristics of rocks in the fault are studied through field investigation, geological mapping, mineral composition analysis, and mechanical tests. In addition, a displacement model of multilevel structure fault is presented by numerical simulation. The results show that the Jinshajiang main fault comprises a primary structure and several secondary weak structures, which has a typical structure of multilevel fault. There are several secondary weak structures in the outcrop of the fracture zone. Compared with the rock masses in the primary structure, the joints of the rock masses in the secondary weak structure are more developed, and the rock particle size is smaller, the mud content is higher, and the mechanical strength is lower. The geometric morphology, mineral composition, and mechanical properties of the rock masses in the secondary weak structure are obviously different from those of the primary structure. The overall displacement mode of multilevel structural fault is S-shaped distribution, and the secondary weak structure will affect the displacement distribution pattern and have the possibility of sliding when the fault moves. Therefore, the secondary weak structure section in the tunnel should be a priority for prevention and control when designing tunnels through active faults. The multilevel structure of the fault, together with centralized structure, distributed structure, and stepped structure of the fault, can be used as a structure classification method of fault structure, which provides a reference for the study of disaster mechanisms, and prevention and control measures of tunnels crossing active faults

    Immune Response of A Novel ATR-AP205-001 Conjugate Anti-hypertensive Vaccine

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    Abstract We developed a virus-like particle (VLP)-based therapeutic vaccine against angiotensin II receptor type 1, ATR-AP205-001, which could significantly reduce the blood pressure and protect target organs of hypertensive animals. In this study, we focused on the immunological effect and safety of the VLP-based vaccine. By comparing to the depolymerized dimeric vaccine ATR-Dimer-001, we found that ATR-AP205-001 reached subcapsular sinus of lymph node shortly after administration, followed by accumulation on follicle dendritic cells via follicle B cell transportation, while ATR-Dimer-001 vaccine showed no association with FDCs. ATR-AP205-001 vaccine strongly activated dendritic cells, which promoted T cells differentiation to follicular helper T cells. ATR-AP205-001 vaccine induced powerful germinal center reaction, which was translated to a boost of specific antibody production and long-lasting B cell memory, far superior to ATR-Dimer-001 vaccine. Moreover, neither cytotoxic T cells, nor Th1/Th17 cell-mediated inflammation was observed in ATR-AP205-001 vaccine, similar to ATR-Dimer-001 vaccine. We concluded that ATR-AP205-001 vaccine quickly induced potent humoral immunity through collaboration of B cells, follicular dendritic cells and follicular helper T cells, providing an effective and safe intervention for hypertension in the future clinical application

    A new model for Thomson-type actuator including the pressure buffer

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    The motion characteristics and flow field variation of Thomson-type actuator have been investigated in this article, in which a two-dimensional axisymmetric cylindrical coordinate model is constructed and described by a set of multi-physical equations reflecting the flow field, transient electromagnetic field, electric circuit, and mechanical motion. The motion performance of the actuator and the pressure drag caused by the high-speed movement of metal plate are analyzed under different opening speeds. It shows that the pressure drag has a strong buffer effect on the actuator. The influence of the laminar and standard k − ε models on the pressure distribution, velocity distribution, and motion characteristics is focused on. In comparison with the laminar model, the pressure drag of the turbulence model is much higher than the laminar model and is more beneficial for the buffer design of the mechanism

    Derivation of Mouse Haploid Trophoblast Stem Cells

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    Summary: Trophoblast stem (TS) cells are increasingly used as a model system for studying placentation and placental disorders. However, practical limitations of genetic manipulation have posed challenges for genetic analysis using TS cells. Here, we report the generation of mouse parthenogenetic haploid TS cells (haTSCs) and show that supplementation with FGF4 and inhibition of Rho-associated protein kinase (ROCK) enable the maintenance of their haploidy and developmental potential. The resulting haTSCs have 20 chromosomes, exhibit typical expression features of TS cells, possess the multipotency to differentiate into specialized trophoblast cell types, and can chimerize E13.5 and term placentas. We also demonstrate the capability of the haTSCs to undergo genetic manipulation and facilitate genome-wide screening in the trophoblast lineage. We expect that haTSCs will offer a powerful tool for studying functional genomics and placental biology. : Trophoblast stem (TS) cells are increasingly used as a model system for studying placentation and placental disorders. Here, Cui et al. report the generation of mouse haploid TS cells, which possess a wide extraembryonic developmental potential and can serve as a powerful tool for studying functional genomics and placental biology. Keywords: haploidy, trophoblast, stem cells, TS
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