4D Flow MRI is a phase-contrast magnetic resonance imaging method that enables direct measurement of velocities in three orthogonal directions throughout the heartbeat. This permits direct quantification of hemodynamic parameters, including flow, mean velocity, peak velocity, and pulsatility, for individual cerebral vessels. Despite ongoing research into neurovascular applications of 4D...
Fluorescence microscopy has become a widely used tool in many research areas. However, its spatial resolution, limited to 250 nm by the diffraction limit of light, has restricted direct observation of details of ultrastructural biology. In recent years, spectroscopic single-molecule localization microscopy (sSMLM), one of super-resolution imaging techniques, has been...
We rely on the properties of our skeletal muscles to traverse our world, interact with objects, and complete everyday tasks. The macroscopic properties of muscles that endow us with these abilities arise from the material properties of muscle fibers and the surrounding extracellular matrix (ECM), as well as how they...
Decisions in naturalistic environments usually feature delayed and uncertain outcomes that can only be reached after a sequence of actions are performed. For example, canonical stalking and pursuit strategies used by terrestrial predators often involve stages of concealment, pauses where the predator remains motionless, and high speed chase sequences. The...
In nature, materials with complex architectures are formed through hierarchical self-assembly. Therefore, the study and design of hierarchically assembling materials is important in producing materials that mimic biological structures and is a key challenge in biomaterials science and engineering. In articular cartilage, hierarchical assembly of extracellular matrix (ECM) components provides...
Single-molecule localization microscopy (SMLM) has significantly stimulated the development of methods to quantitatively visualize and characterize biomolecules in vitro and in situ. SMLM is a class of super-resolution microscopy (SRM) techniques, which exploits the “on-off” switching of individual fluorescent molecules to estimate their location with nanometer precision and offers spatial...
Atrial fibrillation (AF) is the most common cardiac arrhythmia, and associated with increased risk for ischemic stroke and mortality. While the risk of stroke has been shown to be reduced with the use of oral anticoagulants like Warfarin, these medications are predictably linked with an increased risk of bleeding, and...
The goal of the work reported here was to answer two important questions with regards to LTVV use for patients with ARDS: 1) How do we measure adoption? and 2) What are the drivers of provider adoption? To this end, I have demonstrated the influence of patient height, hypoxemia severity,...
Atrial fibrillation (AF) is the most common arrhythmia in adults in the United States. Despite its prevalence, the etiology of AF and its adverse effects are not completely understood, which has made treatment of AF difficult. However, left atrial (LA) fibrosis is associated with worsening and propagating AF. Additionally, research...
Label-free assays, and particularly those based on the combination of mass spectroscopy with surface chemistries, enable high-throughput experiments of a broad range of reactions. However, these methods can still require the incorporation of functional groups that allow immobilization of reactants and products to surfaces prior to analysis. In this thesis,...
Maneuvering your limbs requires both accurate commands for how to move, and accurate feedback of their true movements. Conventional prosthetic arms currently lack this sense of proprioceptive feedback, which can make daily tasks difficult without close visual monitoring. Although studies have successfully provided artificial proprioceptive feedback to improve control, this...
Neurons are sensitive to the mechanical properties of their environment and show better growth, survival and differentiation when they are cultured in soft environments with mechanical properties similar to those of the brain compared to other tissues. Within the central nervous system (CNS), there is also a range of mechanical...
A stroke occurs when blood flow in the brain is impaired and often causes damage to corticospinal tract projections that control the muscles of the upper-extremity. Due to this damage, 50-70% of stroke survivors experience long-term upper-extremity functional deficits(Faria-Fortini, Michaelsen, Cassiano, & Teixeira-Salmela, 2011). These deficits result from motor impairments...
Chromatin, a complex nuclear structure comprised of DNA, histones, RNA, and other nuclear proteins, is one of the most critical components within the cell because it houses the genetic information and its organization regulates important cellular functions, such as transcription, replication, and repair. Its structural organization is well understood at...
Magnetic resonance imaging (MRI) is used widely and frequently in the clinical setting to image and diagnose patients. In addition to the anatomical scans that can be acquired using MRI, different kinds of physiological parameters, such as blood flow, can be obtained by utilizing pulse sequence, scan protocol and post-processing....
Cancer progression is a complex process, leading to metastatic spread of primary tumor cells that colonize distant vital organs and mortality if not stopped. Since clinical strategies to stem this progression are still being developed, it is of great importance to detect this end stage metastatic spread as early as...
End-stage renal disease, or kidney failure, can result from acute kidney injury or sustained kidney damage in the form of chronic kidney disease. As the prevalence of end-stage renal disease continues to rise, the gold-standard treatment—kidney transplantation—is increasingly restricted by the shortage of transplantable donor kidneys. Bioengineered kidney tissues may...
Microfluidic technologies enable multi-tissue culture and precise control of media exchange and therefore have significant potential to create more complex in vitro models of reproductive systems, including endocrine cycles. However, microfluidic technologies have largely been applied to gamete-level culture in reproductive biology, with very little progress in organ-level culture. Herein...
Nanocarriers are nanometer-sized (1-1000 nm) structures capable of encapsulating cargo. This encapsulation can drastically alter the pharmacokinetic properties of the cargo, while also allowing for the rational design and engineering of the nanocarrier itself. Poly(ethylene glycol)-block-poly(propylene sulfide) is an amphiphilic diblock copolymer capable of self-assembling into diverse nanocarriers. The purpose...
Nanomaterials are broadly defined as materials that exhibit at least one dimension that is less than 1,000 nm. Encompassed within nanomaterials are a class of constructs known as nanocarriers, which are applied as delivery vehicles for both encapsulated and covalently bound payloads. Poly(ethylene glycol)-block-poly(propylene sulfide) (PEG-b-PPS) is an amphiphilic block...