Physics

Permanent URI for this collectionhttps://hdl.handle.net/10323/11897

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Enriching quantum systems with dynamic magnon-mediated interactions
(2025-01-01) Trevillian, Cody Alexander; Tyberkevych, Vasyl; Slavin, Andrei; Cholis, Ilias; Louis, Steven; Li, Yi
Quantum technology is trending toward larger, increasingly interconnected networks of diverse platforms, where coherent information transfer among disparate hardware is essential yet challenging. Magnons, the quanta of spin waves, couple strongly to both bosonic and fermionic quantum objects, offering a route to bridge platforms. This dissertation develops dynamic magnon-mediated interactions that use short, shaped magnetic-field pulses to tune the magnon resonance on demand, linking modules only when needed. By choosing the temporal profile, these pulses deterministically set when, how strongly, and for how long hybrid systems interact, enabling unitary operations such as coherent state transfer, interference, and entanglement not accessible with static or quasi-static control.
Dynamic contrast-enhanced mri in rat glioblastoma models: vascular parameters and corrections for systematic errors
(2025-01-01) Acharya, Prabhu Chandra; Xia, Yang; Xia, Yang; Ewing, James R.; Brown, Stephen L.; Nagaraja, Tavarekere N.; Bagher-Ebadian, Hassan
Dynamic contrast-enhanced MRI (DCE-MRI) is widely used in pharmacokinetic modeling to assess biomarkers of treatment response and predictors of tumor progression. Plasma volume fraction (vp), blood-to-tissue forward volumetric transfer constant (Ktrans), and interstitial volume fraction (ve) are the most common biomarkers that explain tumor physiology in embedded cerebral gliomas. DCE-MRI demand stability of receiver sensitivity across the time of study but may suffer from high duty-cycle imaging instability that can bias parameter estimates. In this dissertation, an analysis of DCE-MRI data affected by unstable receiver sensitivity acquired at 7T in a rat model of 9L glioblastoma (GBM) is presented. Phantom studies verified that an unexpected variation in Ktrans in 9L rat model of gliosarcoma was the result of reduction in receiver signal amplitude, indicating a baseline signal drift. Cooling the coil and repeating the experiment pointed to heating of the coil as the root of the problem, a finding confirmed by the vendor. A correction to the amplitude drift based on a heuristic logarithmic function is presented.Two patient-derived orthotopic xenograft (PDOX) models of GBM (HF3016 and HF3177) were characterized using multiparametric MRI. Vascular and tumor microenvironmental (TME) parameters (vp, Ktrans, ve, VD, tumor exudate flux) were estimated with DCE-MRI along with multiparametric MRI. DCE data were analyzed voxel-wise using Patlak, extended Patlak, and Logan methods, with a data-driven model selection approach for defining the tumor and the normal tissue regions. While vascular and diffusion parameters showed no significant differences between the two models (p>0.05), Flux strongly correlated with VD at the tumor rim. These data report physiological properties of untreated GBM that are representative of human disease both geno- and pheno-typically. Tumor interstitial fluid pressure (TIFP) was measured using the invasive technique in treatment naïve and in irradiated 9L gliosarcoma cerebral tumors in rats. The signatures of acute treatment response were investigated using DCE-MRI. Parameters Ktrans, ve ,VD and Flux, were assessed in these cohorts in paired experiments 24 hours apart, with intervening radiotherapy (RT) in the treatment animals. TIFP and tumor blood flow were significantly reduced (p<0.05) post RT. DCE-MRI biomarkers showed a decrease post RT; notably Flux and VD significantly decreased post RT (p<0.05) and were strongly correlated indicating a clear signature of radiation response. The regression fits of Flux versus VD also differed (p<0.05) between the two cohorts.
Multimodal Imaging Assessment of Post-traumatic Osteoarthritis Progression
(2025-01-01) Singh, Amanveer; Xia, Yang; Xia, Yang; Roth, Bradley J; Surdutovich, Eugene; Jiang, Quan; Puwal, Steffan
Osteoarthritis (OA) is a complex joint disease that can cause progressive damage that leads to chronic pain, stiffness, and functional impairment, which can severely affect the quality of a person’s life. The primary reason for the development of OA is the degeneration of articular cartilage which acts as a smooth load-bearing surface in diarthrodial joints. Post-traumatic osteoarthritis (PTOA) is a specific form of OA that occurs after joint injury. The architecture and operation of articular cartilage are special and depend on its dense extracellular matrix (ECM); PTOA results in significant ECM changes which lead to cartilage degradation and structural failure. Due to the avascular nature of cartilage, its self-repair capacity remains limited, thus its degradation will benefit from early detection and intervention. The study of PTOA progression is critically dependent on advanced imaging methods. For example, magnetic resonance imaging (MRI) is a sensitive tool for detailed assessment of cartilage health and can assist in the early detection of disease; polarized light microscopy (PLM) is effective for the detailed assessment of collagen fiber orientation and structural integrity of the cartilage; and computed tomography (CT) imaging can measure subchondral bone remodeling. These imaging techniques probe different aspects of cartilage degradation; when used in combination, they can help to better understand OA progression which can lead to early diagnosis and more effective intervention.This dissertation consists of eight chapters that investigate PTOA progression through high-resolution imaging. The first three chapters introduce this dissertation research by explaining knee joint OA while reviewing literature about its pathophysiology and advanced imaging capabilities for detecting early disease changes. The experimental design and imaging approaches for studying topographical and depth-dependent cartilage changes are explained in Chapter Four. The dissertation presents three peer-reviewed journal articles in chapters five through seven, offering new insights into cartilage degeneration in OA. Chapter Five explores the progression of PTOA and biomechanical factors involved in PTOA progression using μMRI imaging of the whole knee joint. Chapter Six investigates zonal structural changes in articular cartilage following a mechanical injury utilizing high-resolution μMRI imaging of cartilage blocks. Chapter seven examines the effects of an impact injury on articular cartilage and subchondral bone through PLM and μCT imaging. The final chapter summarizes results of this dissertation study and discusses potential future research directions.
Bose-Einstein Condensation of Magnons in Ferromagnets and Antiferromagnets
(2025-01-01) Artemchuk, Petro; Slavin, Andrei; Slavin, Andrei; Tyberkevych, Vasyl; Srinivasan, Gopalan; Tonyushkin, Alexey
Bose-Einstein condensation is a collective phenomenon which is the process of transition of many bosons - particles having integer spin - to the same coherent quantum state. One of the examples of bosons are magnons - the quanta of spin waves propagating in magnetic media. Formation of Bose-Einstein condensate (BEC) of magnons has been observed experimentally in ferromagnetic (FM) materials and analyzed in theory. The peculiarity is that BEC of magnons can be formed at room temperature. The BEC of magnons exhibits dynamic properties related to transport of magnon density, which appears to be anisotropic. In addition, the BEC of magnons also possesses nonlinear properties related to interaction of magnons in BEC and responsible for its stability. However, the theory available does not take into account all the important factors. Antiferromagnetic materials (AFM) also allow for existence of magnons, which implies the possibility of BEC formation in AFM materials as well. Although such a possibility has been discussed multiple times, none of the methods proposed has been realized on practice yet. The dissertation first informs about relevant topics, covering principles of magnonics, formation of BEC and its properties. It then describes a model aimed to describe both transport and nonlinear properties of magnons in BEC while accounting for all the peculiarities of magnons. After this, it explores in theory the interaction of magnon gas in the process of BEC formation with an isolated low-frequency mode. Finally, it delves into formation of BEC in AFM samples using a method of rapid cooling. It analyzes conditions required for BEC formation and discusses possible practical realization. The research presented in the dissertation helps to understand complicated phenomena related to formation and existence of BEC. It also opens new possibilities and directions of research both theoretical and experimental ones
Neuromorphic Computing with Antiferromagnetic Artificial Neurons
(2024-01-01) Bradley, Hannah D; Tyberkevych, Vasyl; Tyberkevych, Vasyl; Slavin, Andrei; Khain, Evgeniy; Bozhko, Dmytro
The increasing focus on Artificial Intelligence (AI) presents notable challenges, especially in the power requirements essential for training AI models. Consequently, there is a growing emphasis on neuromorphic computing, which aims to construct Artificial Neural Networks (ANNs) from artificial neurons to replicate the speed and efficiency of the human brain. With their significantly lower power consumption, spintronic devices acting as artificial neurons offer the potential for ANNs that rival conventional components. This innovative approach not only tackles the energy efficiency challenges but also paves the way for advancements in neuromorphic computing by integrating magnetic materials and spin-dependent effects. Antiferromagnetic (AFM) materials, characterized by their inherent THz frequencies, provide a unique opportunity for spintronic devices with ultra-fast dynamics. There's a proposal to utilize AFM materials to craft ultra-fast spin-Hall oscillators. These oscillators emit spiking signals resembling those of biological neurons, indicating their potential as artificial neurons. AFM oscillators exhibit exceptionally fast characteristics, including picosecond-scale spike widths and unique features absent in conventional artificial neuron models. This research examines the utilization of AFM oscillators as artificial neurons and their significance in the realm of neuromorphic computing. This dissertation begins with a comprehensive overview of relevant topics, covering the principles of spintronics, AFM materials, and neuromorphic computing. It examines the unique dynamics of AFM neurons, such as response latency and refraction time, which arise from an effective internal inertia. Then, it explores innovative AFM neuron circuits that exhibit functionalities unattainable by conventional artificial neurons, such as non-monotonic inhibition. Additionally, conventional learning algorithms like backpropagation are use to train AFM ANNs for pattern recognition. Finally, it leverages the similarities between AFM and biological neurons to model the biological neural network responsible for the withdrawal reflex. With their simplistic design and high speeds, AFM neurons exhibit energy efficiencies several orders of magnitude higher than traditional artificial neurons and even other spintronic designs. This suggests that AFM ANNs will excel at training AI models while addressing the energy crisis impeding technological progress. As a result, AFM neurons drive forward the progress of spintronic neuromorphic computing, providing a promising alternative for future technological development
Cerebral Waste Clearance: Measurements and Applications
(2023-01-01) Kaur, Jasleen; Xia, Yang; Roth, Bradley J; Zhang, Li; Zhang, Zhenggang; Chopp, Michael
Cerebral Waste clearance (CWC) is an essential process for brain homeostasis, which is required for the healthy functioning of all cerebrovascular and parenchymal brain cells. This dissertation features our current understanding of CWC, both within and external to the brain parenchyma. We describe the role of the cerebrospinal fluid (CSF) and its exit routes in mediating CWC. Recent discoveries of the glymphatic system and meningeal lymphatic vessels (mLVs), and their relevance to CWC and various neurological conditions are highlighted. Controversies related to CWC research and potential future directions are presented. This dissertation is divided into seven chapters that discuss investigations that used magnetic resonance imaging (MRI) and confocal microscopy imaging to evaluate the recently identified CWC routes, namely the glymphatic system and the mLVs. The dissertation begins with an introduction (Chapter- 1). It proceeds with background (Chapter- 2) based on two published peer-reviewed ‘review’ articles, and three research projects based on one submitted, one published ‘original research’ articles (Chapters- 3, 4) and one project with negative results (Chapter- 5). Among the three projects described in this dissertation, the first project (Chapter- 3) aimed to investigate the controversy of glymphatic convective bulk flow in the interstitial spaces and explore the association of perivascular macrophages (PVMs) in assisting the glymphatic system for CWC. Our findings solidify the glymphatic system hypothesis and indicate the interaction of PVMs with the glymphatic CSF influx along the arteries and glymphatic CSF efflux along the veins. The second project (Chapter- 4) aimed to examine the changes in the glymphatic system in rats with glioblastoma multiforme (GBM) and our results identify reduced glymphatic influx and clearance due to GBM. The third project (Chapter- 5) aimed to assess the mLVs as a potential efflux pathway of the glymphatic system under healthy and diabetic mellitus (DM) conditions. Our results suggest that mLVs are not the major efflux pathway of the glymphatic system, which is a negative result. The dissertation then discusses a translational issue for clinical MRI evaluation of the glymphatic system (Chapter- 6) based on a submitted ‘review’ article and concludes with a summary and future directions (Chapter- 7).
Experimental and Computational Studies of Articular Cartilage at High Resolutions
(2023-01-01) Batool, Syeda S.; Xia, Yang; Roth, Bradley John; Bowyer, Susan; Puwal, Steffan; Tonyushkin, Alexey
Articular cartilage is a thin layer of connective tissue covering the ends of bones in diarthrodial joints to minimize friction and distribute loads. The degradation of articular cartilage is the hallmark of osteoarthritis (OA), a complex joint disease that ranks as the number one cause of disability in the adult population. Conceptually, cartilage can be divided into three sub-tissue zones (the superficial zone SZ, the transitional zone TZ, and the radial zone RZ) across its thin thickness (depth), where each zone has a set of unique depth-dependent properties. These uneven structural and compositional variations across its thin thickness imply that any diagnostic technique should ideally have high resolution in imaging; otherwise, volume averaging within an image pixel could obscure any possibility of early disease detection.In this dissertation, we used quantitative microscopic magnetic resonance imaging (µMRI) combined with polarized light microscopy (PLM) to study the articular cartilage in rabbits and its potential use as an animal model for OA. The utilization of animals plays a vital role in OA research, which enables the examination of the degradation of OA before any procedures are used on humans in the clinic. This dissertation has six chapters. Chapters 1 and 2 contain the introduction, the background, and the literature review. Chapter 3 is an experimental MRI and PLM study of rabbit cartilage at sub-10 µm resolution, which established quantitatively the baseline characteristics of healthy rabbit cartilage between µMRI and PLM. The results, which are useful for the future investigation of OA using the rabbit model, have been published in the Journal of Orthopaedic Research (Batool & Xia, 2020). Chapter 4 is an experimental study to characterize the structural variations at different anatomical locations of femoral cartilage in young rabbits (12-14 weeks old) using µMRI and PLM. Knowledge of location-specific structural differences in the collagen network over the joint surface can improve the understanding of local mechanobiology and provide insights into tissue engineering, and degradation repairs This study has been published in the journal Cartilage (Batool & Xia, 2022). Chapter 5 presents a computational study that used a mathematical model to describe the role of collagen fibril mechanics in articular cartilage under 1D axial compression. This study is being finalized for a peer-reviewed journal. The final Chapter 6 summarizes this dissertation.
Structural Characteristics of Articular Cartilage in the Early Detection of Post-Traumatic Osteoarthritis by Microscopic Imaging Techniques
(2023-01-01) Mantebea, Hannah; Xia, Yang; Roth, Bradley j; Khain, Evgeniy; Surdutovic, Eugene; Quan, Jiang
Cartilage is a specialized form of connective tissue that provides support and cushioning to adjacent tissues in the body. Cartilage is of three types: Hyaline, fibrocartilage, and elastic. The articular cartilage is a hyaline type and is the most found throughout the animal and human bodies. Articular cartilage is composed of a dense extracellular matrix (ECM) with specialized cells, and chondrocytes, which are sparsely distributed. The ECM is primarily made up of collagen, proteoglycan, water, non-collagenous proteins, and glycoproteins. The components of the ECM are subject to change in the disease state, especially in osteoarthritis. As a result of the complex and unique nature of the articular cartilage, early detection, treatment, and repair pose a challenge in clinic. Imaging techniques such as magnetic resonance imaging (MRI) has been used in the noninvasive evaluation of the cartilage structure, and polarized light microscopy (PLM) allows the examination of the molecular organization at optical resolution.The first project in this dissertation aimed to study the structural characteristics of the articular cartilage in the patella and the fibrocartilage of the suprapatella in the knee joint. This was achieved quantitatively using µMRI and PLM at both low and high resolutions. The second project in this dissertation aimed to compare the structures between the immature and mature articular cartilage of the femur and humerus qualitatively and quantitatively using µMRI and PLM. The third project in this dissertation was aimed at the structural characteristics of the articular cartilage in the disease state. Specifically qualitative and quantitative characteristics from traumatized joints (post-traumatic osteoarthritis) were studied using µMRI and PLM at high resolutions. These studies confirmed the ability of µMRI and PLM to examine the cartilage structure quantitatively and qualitatively in a healthy state and in a diseased state. The ability to study the microscopic anatomy of cartilage and pathology (osteoarthritis) in the early stage will contribute to the treatment and early diagnosis of arthritis.

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