Small-scale, low-mass embedded systems have received significant interest in a variety of applications as the capabilities of embedded electronics have increased. Examples of new realizable ...applications are self-reliant bio-loggers and tracking tags for small animals. Due to the small scale and low power levels, the power management for these systems presents significant challenges. In this dissertation, research will be presented on various aspects of the flow of energy on a self-reliant embedded system. First, an investigation into the dynamics of combining the power from multiple energy harvesting devices will be shown. The work provides guidelines for energy harvesting systems combining photovoltaic and piezoelectric devices as well as an array of multiple piezoelectric devices. Using the knowledge gained from this work, effective multi-source energy harvesting systems can be designed. Next, a novel method for the low-loss AC-DC rectification of a vibration energy harvester is presented and evaluated. The new rectification technique allows for more efficient power conversion in addition to the rectification of low-voltage harvesting systems. This is performed without active electrical circuitry and does not require external power sources for full operation. The last topic is the investigation of the energy storage design challenges for a self-reliant avian bio-logger. Prototypical operation requirements are developed to determine the most pertinent challenges and a preliminary system design is presented and evaluated. Using the analyses performed on the prototypical system, new small-scale self-reliant embedded systems can be realized to further increase the tools scientists have at their disposal for understanding the behavior of small animals.
Thesis advisor: Dorothy Jones
Background/Purpose: The growth of clinical research trials to improve patient outcomes has significantly affected nursing and the implementation of the nurse research ...coordinator role. The purpose of this study was to explore how the research nurse coordinator (RNC) perceives this role and associated responsibilities for patients enrolled in a clinical research study and associated problems and ethical tensions that emerge during the delivery of a clinical research protocol. The research questions were 1) How does the RNC perceive his or her role responsibility for patients enrolled in a clinical trial? 2) Does the nurse experience ethical tension during the implementation of the RNC role? Methods: A qualitative descriptive study was used to answer the questions. RNCs from a large Northeastern teaching hospital participated in 1:1 interviews with the investigator. Data were analyzed for this study according to the methods described in Lincoln and Guba (1985) for qualitative research and presented as themes. Results: Eleven RNC participated in the study. Data from the interviews were distilled into five final themes: 1) The RNC develops intentional and mutual relationships with patients and their families that fosters trust; 2) In coming to know the patient the RNC as a clinical expert is able to advocate for the unique needs of patients enrolled in clinical trials; 3) The RNC is respected by the team for his or her skills and as a result is able to practice autonomously; 4) In reflecting on past experiences, RNCs identify with medical science philosophy of cure as opposed to nursing’s one of caring/healing and; 5) In reflecting on some aspects of clinical trials, RNCs recognize ethical tensions and as such are able to influence protocol implementation and future studies. Knowledge gained from this study provides insights about the RNC role perception and highlighted multiple dimensions of care delivery faced by nurses who practice as an RNC. The study participants described practicing in the RNC role with clarity about the role and described practicing with autonomy and independence.
Thesis (PhD) — Boston College, 2016.
Submitted to: Boston College. Connell School of Nursing.
Discipline: Nursing.
We sought to determine real-world accuracy of inpatient continuous glucose monitoring (CGM) at multiple levels of acuity in a large safety-net hospital.
We analyzed records from hospitalized patients ...on Dexcom G6 CGM, including clinical, point of care (POC), and laboratory (Lab) glucose, and CGM data. POC/Lab values were matched to the closest timed CGM value. Encounters were divided into not critically ill (NCI) versus critically ill (CI). CGM accuracy was evaluated.
Paired readings (2,744 POC-CGM; 3,705 Lab-CGM) were analyzed for 233 patients with 239 encounters (83 NCI, 156 CI). POC-CGM aggregated and average mean absolute relative differences (MARD) were 15.1% and 17.1%. Lab-CGM aggregated and average MARDs were 11.4% and 12.2%. Accuracy for POC-CGM and Lab-CGM was 96.5% and 99.1% in Clarke Error Grid zones A/B.
Real-world accuracy of inpatient CGM is acceptable for NCI and CI patients. Further exploration of conditions associated with lower CGM accuracy in real-world settings is warranted.
Chemical-level details such as protonation and hybridization state are critical for understanding enzyme mechanism and function. Even at high resolution, these details are difficult to determine by ...X-ray crystallography alone. The chemical shift in NMR spectroscopy, however, is an extremely sensitive probe of the chemical environment, making solid-state NMR spectroscopy and X-ray crystallography a powerful combination for defining chemically detailed three-dimensional structures. Here we adopted this combined approach to determine the chemically rich crystal structure of the indoline quinonoid intermediate in the pyridoxal-5′-phosphate-dependent enzyme tryptophan synthase under conditions of active catalysis. Models of the active site were developed using a synergistic approach in which the structure of this reactive substrate analogue was optimized using ab initio computational chemistry in the presence of side-chain residues fixed at their crystallographically determined coordinates. Various models of charge and protonation state for the substrate and nearby catalytic residues could be uniquely distinguished by their calculated effects on the chemical shifts measured at specifically 13C- and 15N-labeled positions on the substrate. Our model suggests the importance of an equilibrium between tautomeric forms of the substrate, with the protonation state of the major isomer directing the next catalytic step.
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