DEVELOPMENT AND APPLICATIONS OF FEATURE-GUIDED CARDIAC MOTION ESTIMATION METHODS FOR 4D CARDIAC PET

The aim of this dissertation research is to develop, implement and evaluate methods to extract useful information about cardiac motion and myocardial contractility from 4D cardiac PET images with much improved image quality. First, to reduce the influence of respiratory motion and improve the quality of cardiac PET images used in motion estimation, data-driven respiratory gating methods are proposed to allow accurate extraction of respiratory motion signal from the list-mode data. Time-of-flight PET information is incorporated into respiratory signal extraction, and background correction method is developed to improve the quality and accuracy of the extracted respiratory signal. The methods were applied and evaluated using clinical list-mode cardiac PET data. With improved image quality, anatomical feature such as papillary muscles and the interventricular sulcus become increasingly detectable in gated cardiac PET images. For more accurate cardiac motion estimation, these anatomical features in human heart were extracted and used in combination with a priori knowledge of cardiac function to guide the cardiac motion estimation process. Initial estimates of the cardiac motion vector field were obtained based on the motion of the features for the traditional optical-flow algorithm. For further improvement, motion of the anatomical feature was used as additional constraint in the motion estimation algorithm to reduce the effect of the classical aperture problem. Different from previous cardiac motion extraction and estimation studies that only provide qualitative evaluation of the motion estimation results due to unavailability of ground truth for clinical cardiac datasets, this study employed simulation data from a realistic digital phantom with known cardiac motion for both qualitative and quantitative evaluation. Motion estimation results from simulation data indicate the feature-based cardiac motion estimation method is able to improve the accuracy of the cardiac motion field estimates, especially for motion components parallel to edges and therefore difficult to estimate using the conventional optical-flow based method. The proposed research will allow PET imaging to provide unprecedented cardiac motion information in addition to its functional information thus improving diagnosis of cardiac diseases including perfusion and motion abnormalities, and patient care with reduced cost. Also, more accurate estimation of cardiac motion will help to further improve the quality of 4D cardiac PET imaging with cardiac motion compensation

A model local interpretation routine for deep learning based radio galaxy classification

Radio galaxy morphological classification is one of the critical steps when producing source catalogues for large-scale radio continuum surveys. While many recent studies attempted to classify source radio morphology from survey image data using deep learning algorithms (i.e., Convolutional Neural Networks), they concentrated on model robustness most time. It is unclear whether a model similarly makes predictions as radio astronomers did. In this work, we used Local Interpretable Model-agnostic Explanation (LIME), an state-of-the-art eXplainable Artificial Intelligence (XAI) technique to explain model prediction behaviour and thus examine the hypothesis in a proof-of-concept manner. In what follows, we describe how \textbf{LIME} generally works and early results about how it helped explain predictions of a radio galaxy classification model using this technique.Comment: 4 pages, 1 figure, accepted summary paper for URSI GASS 2023 J0

Sustainable utilization of bauxite residue (Red Mud) as a road material in pavements: A critical review

Sustainable utilization of the bauxite residue (red mud) generated from the alumina refining has recently increased due to increased environmental concerns because of its high alkalinity and problematic pollutants when placed in landfills. This paper attempts to review recent research findings of utilizing red mud as a road material in pavement structures in literature, including road bases and asphalt mixtures. Previous laboratory investigations indicated that red mud is feasible to be used as a raw material in road bases with satisfactory unconfined compressive strength (UCS), frost resistance and durability performance, but their durability during the service life of the pavement is still unclear. The incorporation of red mud in asphalt mastics was found to be able to improve its stiffness, such as softening point, complex modulus, and viscosity. In terms of asphalt mixtures, replacing limestone filler in mixtures by red mud resulted in some positive effects on mechanical behaviors, high bulk density and good rutting resistance. However, the moisture susceptibility and raveling resistance of asphalt mixtures became relatively worse because of the addition of red mud. Referring to this overview, it is necessary to qualify the long-term service performance of road base materials prepared with red mud by using laboratory accelerating evaluation or road trials. For asphalt mixtures prepared with red mud, how to improve durability, in particular moisture resistance, will be a future research focus. In addition, the influence of red mud on cracking resistance at low temperature, fatigue properties and long-term durability of asphalt mixtures is still needed to be further explored

The Influence of Dietary Gallic Acid on Growth Performance and Plasma Antioxidant Status of High and Low Weaning Weight Piglets.

peer reviewedThis study evaluated the effects of dietary gallic acid (GA) on growth performance, diarrhea incidence and plasma antioxidant status of weaned piglets regardless of whether weaning weight was high or low. A total of 120 weaned piglets were randomly allocated to four treatments in a 42-day experiment with a 2 × 2 factorial treatment arrangement comparing different weaning weights (high weight (HW) or low weight (LW), 8.49 ± 0.18 kg vs. 5.45 ± 0.13 kg) and dietary treatment (without supplementation (CT) or with supplementation of 400 mg/kg of GA). The results showed that HW piglets exhibited better growth performance and plasma antioxidant capacity. Piglets supplemented with GA had higher body weight (BW) on day 42 and average daily gain (ADG) from day 0 to 42 compared to the control piglets, which is mainly attributed to the specific improvement on BW and ADG of LW piglets by the supplementation of GA. The decreased values of diarrhea incidence were seen in piglets fed GA, more particularly in LW piglets. In addition, dietary GA numerically reduced malondialdehyde (MDA) content in plasma of LW piglets. In conclusion, our study suggests that dietary GA may especially improve the growth and health in LW weaned piglets

Polyoxometalate-supported Pd nanoparticles as efficient catalysts for the direct synthesis of hydrogen peroxide in the absence of acid or halide promoters

A Keggin-type polyoxometalate (Cs1.5H1.5PW12O40)-supported Pd catalyst is efficient for the direct synthesis of H2O2 from H-2 and O-2 in the absence of any acid or halide additives under atmospheric pressure.NSFC [20625310, 20773099, 20873110]; National Basic Research Program of China [2005CB221408]; Program for New Century Excellent Talents in Fujian Provinc

NiO-polyoxometalate nanocomposites as efficient catalysts for the oxidative dehydrogenation of propane and isobutane

Novel nanocomposites of NiO and polyoxometalate (Cs2.5H0.5PMo12O40) with particle sizes in the range of 5-10 nm showed exceptional oxygen and ammonia adsorption capabilities, and the nanocomposites catalyzed the oxidative dehydrogenation of propane and isobutane efficiently under mild conditions.NSFC [20625310, 20773099, 20873110]; National Basic Research Program of China [2005CB221408]; Program for New Century Excellent Talents in Fujian Provinc

H9N2 virus-derived M1 protein promotes H5N6 virus release in mammalian cells: Mechanism of avian influenza virus inter-species infection in humans

H5N6 highly pathogenic avian influenza virus (HPAIV) clade 2.3.4.4 not only exhibits unprecedented intercontinental spread in poultry, but can also cause serious infection in humans, posing a public health threat. Phylogenetic analyses show that 40% (8/20) of H5N6 viruses that infected humans carried H9N2 virus-derived internal genes. However, the precise contribution of H9N2 virus-derived internal genes to H5N6 virus infection in humans is unclear. Here, we report on the functional contribution of the H9N2 virus-derived matrix protein 1 (M1) to enhanced H5N6 virus replication capacity in mammalian cells. Unlike H5N1 virus-derived M1 protein, H9N2 virus-derived M1 protein showed high binding affinity for H5N6 hemagglutinin (HA) protein and increased viral progeny particle release in different mammalian cell lines. Human host factor, G protein subunit beta 1 (GNB1), exhibited strong binding to H9N2 virus-derived M1 protein to facilitate M1 transport to budding sites at the cell membrane. GNB1 knockdown inhibited the interaction between H9N2 virus-derived M1 and HA protein, and reduced influenza virus-like particles (VLPs) release. Our findings indicate that H9N2 virus-derived M1 protein promotes avian H5N6 influenza virus release from mammalian, in particular human cells, which could be a major viral factor for H5N6 virus cross-species infection

Mink is a highly susceptible host species to circulating human and avian influenza viruses

Pandemic influenza, typically caused by reassortment of human and avian influenza viruses, can result in severe or fatal infections in humans. Timely identification of potential pandemic viruses must be a priority in influenza virus surveillance. However, the range of host species responsible for the generation of novel pandemic influenza viruses remain unclear. In this study, we conducted serological surveys for avian and human influenza virus infections in farmed mink and determined the susceptibility of mink to prevailing avian and human virus subtypes. The results showed that farmed mink were commonly infected with human (H3N2 and H1N1/pdm) and avian (H7N9, H5N6, and H9N2) influenza A viruses. Correlational analysis indicated that transmission of human influenza viruses occurred from humans to mink, and that feed source was a probable route of avian influenza virus transmission to farmed mink. Animal experiments showed that mink were susceptible and permissive to circulating avian and human influenza viruses, and that human influenza viruses (H3N2 and H1N1/pdm), but not avian viruses, were capable of aerosol transmission among mink. These results indicate that farmed mink could be highly permissive “mixing vessels” for the reassortment of circulating human and avian influenza viruses. Therefore, to reduce the risk of emergence of novel pandemic viruses, feeding mink with raw poultry by-products should not be permitted, and epidemiological surveillance of influenza viruses in mink farms should be urgently implemented