Transfer Functions for Fast Electromagnetic and Circuit Modeling

As the electronics industry continues to grow at a rapid pace, the need for faster and yet more accurate computer-aided simulation tools is at an all time high. Engineers need to perform accurate simulations in an expedient enough fashion to guide design decisions during the design stage of an electrical component or a system. This thesis presents a set of such models used as part of a modeling and simulation framework for electromagnetic interference aware electronic system integration. By leveraging basic electromagnetic principles and boundary conditions, transfer functions were created to model different types of transmission lines and other circuit components in a way that allowed them to be integrated as building blocks of a larger system.Ope

Effect of Long-Term Exposure to Lower Low-Density Lipoprotein Cholesterol Beginning Early in Life on the Risk of Coronary Heart Disease A Mendelian Randomization Analysis

ObjectivesThe purpose of this study was to estimate the effect of long-term exposure to lower plasma low-density lipoprotein cholesterol (LDL-C) on the risk of coronary heart disease (CHD).BackgroundLDL-C is causally related to the risk of CHD. However, the association between long-term exposure to lower LDL-C beginning early in life and the risk of CHD has not been reliably quantified.MethodsWe conducted a series of meta-analyses to estimate the effect of long-term exposure to lower LDL-C on the risk of CHD mediated by 9 polymorphisms in 6 different genes. We then combined these Mendelian randomization studies in a meta-analysis to obtain a more precise estimate of the effect of long-term exposure to lower LDL-C and compared it with the clinical benefit associated with the same magnitude of LDL-C reduction during treatment with a statin.ResultsAll 9 polymorphisms were associated with a highly consistent reduction in the risk of CHD per unit lower LDL-C, with no evidence of heterogeneity of effect (I2 = 0.0%). In a meta-analysis combining nonoverlapping data from 312,321 participants, naturally random allocation to long-term exposure to lower LDL-C was associated with a 54.5% (95% confidence interval: 48.8% to 59.5%) reduction in the risk of CHD for each mmol/l (38.7 mg/dl) lower LDL-C. This represents a 3-fold greater reduction in the risk of CHD per unit lower LDL-C than that observed during treatment with a statin started later in life (p = 8.43 × 10−19).ConclusionsProlonged exposure to lower LDL-C beginning early in life is associated with a substantially greater reduction in the risk of CHD than the current practice of lowering LDL-C beginning later in life

Traction force optical coherence microscopy: a new method to study the dynamic mechanical behavior of cells and multicellular collectives within scattering media

411 pagesMechanobiology is a prominent research field which seeks to elucidate the role of physical forces and mechanical interactions throughout various biological processes, including morphogenesis, wound healing, and cancer metastasis, among others. Traction force microscopy (TFM) is an important family of experimental techniques used by mechanobiologists to study and quantify the forces that cells exert upon their surroundings. Recent years have seen a growing demand for TFM methods capable of studying the dynamic, 3D, and collective behaviors of cells embedded within optically scattering media. However, traditional imaging modalities for TFM (e.g., confocal microscopy) do not currently allow researchers to satisfy these demands. In this dissertation, I present traction force optical coherence microscopy (TF-OCM), a TFM platform based on optical coherence tomography (OCT), to address the as yet unmet imaging needs of mechanobiology researchers and study the dynamic mechanical behavior of cells and multicellular collectives within scattering media. In the first half of this dissertation, I summarize current methods and emerging needs of the TFM field and provide detailed derivations and discussions regarding signal processing methods for OCT imaging. In the latter half, I present the key experimental findings of my research. A pilot study was first performed to demonstrate the ability of OCT imaging to capture substrate deformations induced by cellular traction forces (CTFs). This was followed by a proof-of-concept study which enabled the quantitative reconstruction of time-varying CTFs exerted by isolated cells, resulting in the realization of TF-OCM as a full-fledged experimental technique. The critical image reconstruction procedures developed along the way have since proven useful in the context of other OCT imaging applications as well. Finally, a collaborative application-focused study was performed, which demonstrated the ability of TF-OCM to study the dynamics of large multicellular collectives embedded within scattering collagen substrates. Although much work remains to be done in order to enable quantitative TF-OCM in such complex settings, these findings show that TF-OCM offers a promising avenue to pursue new and valuable research endeavors in mechanobiology

The Influence of Crown Ferrule on Fracture Resistance of Endodontically Treated Maxillary Central Incisors

Background: Prefabricated zirconia posts can contribute to increasing the fracture resistance of the endodontically treated teeth. Purpose. This in vitro study compared the fracture resistance of endodontically treated central maxillary incisors prepared with 2 mm ferrule length to the ones without ferrule

CT Evaluation of the Tracheobronchial Tree in Swine.

Swine are commonly used for research on the respiratory system, but various anatomic features of the tracheobronchial tree of swine are poorly defined. The purpose of our study was to acquire normative measurements of the tracheobronchial tree of swine by using chest CT scans, thus laying a foundation for treating or studying airway disorders in this species. In our study, 33 male swine underwent thoracic CT scans; we measured anatomic features of the tracheobronchial tree, including the diameter, length, and angle of various airway structures. We further analyzed the relationships among selected principal parameters. Our data revealed several similarities and differences in anatomy between swine and humans. This information may be useful in future research

Hidden threat in familial Mediterranean fever: subclinical inflammation, oxidative stress and their relationship with vitamin D status

Background/aim: Vitamin D levels have been investigated in children with familial Mediterranean fever (FMF), but the relationship between vitamin D status and inflammation/oxidative stress indicators could not be clearly demonstrated. This study aimed to investigate the relationship between subclinical inflammation/oxidative stress and vitamin D status in children with FMF during an attack-free period. Materials and methods: In the cross-sectional study, ninety children with FMF in the attack-free period and 30 healthy children were included. Patients were grouped according to their vitamin D status (= 0.640) and high TOS levels were negatively associated with vitamin D levels. Conclusion: Subclinical inflammation and oxidative stress were negatively associated with vitamin D levels in patients with FMF during an attack-free period. Sufficient vitamin D levels are important in fighting subclinical inflammation and oxidative stress in children with FMF