Cold Atmospheric Plasma: An Inside Look Through Optical Diagnostics for Biomedical Applications

An emerging technology for medical applications is cold atmospheric plasma (CAP). CAP is generated using various gasses in a “pen” to create room temperature plasma and then carry the effluents and species. Success has been shown when cold atmospheric plasma is applied to oncology treatments, accelerated wound healing, pathogen disinfection, and various material-changing effects. However, the mechanisms behind these effects are still speculative. This study uses multiple diagnostic techniques including fast photography, two wavelength emission spectroscopy and optical emission spectroscopy to characterize the plasma properties and eventually further test the plasma’s interaction with biological samples. The plume dynamics are observed using fast photography methods, allowing determining visible intensity, plume length, and peak intensity, as gas flow rates and mixture are varied. A two wavelength emission spectroscopy approach is used for determination of plume temperature, using narrow band optical filters at 480 nm and 510 nm. Pixel-by-pixel, ratio of intensities is used to predict the temperature with novel image processing code. Optical emission spectroscopy is used to determine the chemical species along the plume length. The temperature of the plume is found to be slightly above room temperature at the core and then cools towards the tip. The temperature varies with intensity and peaks around 6.5lpm with pure argon and varies with gas mixture. Pure argon has the greatest intensity and plume length. The plume seems to be mostly comprised of reactive oxygen and nitrogen agents (RONS). It is likely these RONS that cause the various effects, especially in oncology

Increasing STEM Literacy Through Directed Outreach

5th Annual Engagement and Service-Learning Summit: Connecting Through Listening and Scholarship, Thursday February 28th, 2019, Hosted by the Office of Engagement and Purdue Honors Colleg

Exploring the Effect of Sample Properties on Spark-Induced Breakdown Spectroscopy

Optical emission spectroscopy techniques such as laser-induced breakdown spectroscopy (LIBS) and spark-induced breakdown spectroscopy (SIBS) provide portable and robust methods for elemental detection in real-time. Laser-produced emissions are then used for quantitative and qualitative analysis of a sample material with applications in explosives detection. For both techniques, the main obstacles have always been signal intensity, accuracy, and sensitivity of detection. The main advantage of the SIBS method is more safe operation, while still maintaining the portability of the technique. In this study, detailed characterization of spark induced plasma, analyte emission intensity, plasma temperature, electron density, and plasma persistence has been studied for various metallic samples with varying physical properties. Target samples, including Mg, Al, Cu, Ta, Sn, Fe, Co, W, and Mo were chosen based on their diverse set of properties, including: melting point, boiling point, first ionization potential, and conductivity. The role of sample properties on temporal evolution of SIBS signal and plasma characteristics was studied by varying the spark energy from 30 mJ to 180 mJ. Certain parameters such as the conductivity of the material greatly affect the SIBS signal intensity output. Mechanisms of SIBS plasma evolution are discussed in the context of material properties and optimal signal detection approaches are proposed. Principle component analysis is used to determine the dominant material properties that affect the SIBS signal intensity and plasma properties in order to optimize the SIBS intensity in the future

Dielectrically-accurate Tissue Simulating Materials for a Heterogeneous Breast MRI Phantom

Phantoms, which are non-biological test objects, are used to validate a variety of biomedical imaging modalities for accuracy and safety. In MRI, phantoms can be used, specifically, to test safety with regards to SAR and RF heating. This is of particular importance when developing new imaging protocols related to a specific anatomy, MRI use, or other software or hardware updates. Discussed in this thesis is the creation of an anatomically accurate breast phantom for safety testing before use of novel MRI protocols for breast cancer diagnostic imaging. Previous MRI breast phantoms are either homogeneous or have barriers between tissue types, which is not representative of real anatomies. Liquid phantoms are not an accurate representation of how heat is transferred through the body. Additionally, each tissue in the body has it\u27s own unique dielectric property and averaging them into one material is not an accurate representation of biological systems. In the new phantom created, each material is verified for dielectric accuracy as a liquid and gel, using an open-ended coaxial probe. These materials are then combined to construct a breast phantom that is more anatomically accurate than current models, as confirmed with MRI

An Exploration of Graduate Student Mental Health: Faculty Advisors, Mental Health, and Social Media

Graduate students are a critical part of academia and the academic environment. However, literature suggests that graduate students, as a community, are also experiencing concerns with mental well-being. Increasingly stressful life situations and academic rigor as well as a culture of celebrating overwork and the stress of academia, have been linked as contributors toward mental distress and a general decline in well-being for graduate students. One of the biggest factors in determining the success and well-being of graduate students is their faculty adviser. A supportive adviser that is well matched to a student’s interests and working style can likely lead to the graduate students being more likely to graduate, to have increased scholarly output, and to find a job after graduation. It stands, then, that faculty advisers may also have an effect on the mental well-being of their students. However, there is currently a lack of information about how students match with the mentoring and management styles of their advisors as well as how they may find surrogate support systems, such as social media, to persevere during their graduate program or what support gaps they might fill with online communities. Therefore this study explored the needs of graduate students, how graduate students may turn to online communities as an means of support, and how faculty advisors can be better matched with graduate students to help guide them toward success in graduate school. The resulting knowledge from this study can provide insights for developing enhanced methods for 1) matching students and advisors based on management and mentoring styles, 2) understanding the evolution of graduate students needs over time, and 3) establishing more thoughtful admission metrics/processes for graduate schools. In addition, an investigation into social media platforms can help us better understand how graduate students use social media for support during their studies as well as identify some common graduate student challenges and helpful strategies to mitigate these challenges. Ultimately, establishing this knowledge can be one step toward generating a more supportive and collaborative academic community which can in turn support the well-being of graduate students According to the results of this study, the data suggests that graduate students are experiencing stress resulting from differences in the styles of management and mentoring between them and their faculty advisors. This stress can be linked to the pressures placed upon them related to scholarly output without clearly defined objectives for them. Student participants also indicated that they doubted the quality of their graduate work and had the feeling they were not moving forward. Some common challenges described by students via social media posts were linked to the limited guidance and/or mentorship received. In regard to turning to social media for support, it seems as though graduate students tend to use social media platforms to either share negative experiences that they faced or milestones achieved within their graduate programs. The findings suggest that the graduate students may use social media without expecting or receiving feedback on how to handle any challenges posted. In addition, graduate student survey participants also indicated that their advisors used primarily a “coaching style, indicating a low level of advisor involvement, with a high level of student involvement

The diarylquinoline TMC207 for multidrug-resistant tuberculosis

BACKGROUND: The diarylquinoline TMC207 offers a new mechanism of antituberculosis action by inhibiting mycobacterial ATP synthase. TMC207 potently inhibits drug-sensitive and drug-resistant Mycobacterium tuberculosis in vitro and shows bactericidal activity in patients who have drug-susceptible pulmonary tuberculosis. METHODS: In the first stage of a two-stage, phase 2, randomized, controlled trial, we randomly assigned 47 patients who had newly diagnosed multidrug-resistant pulmonary tuberculosis to receive either TMC207 (400 mg daily for 2 weeks, followed by 200 mg three times a week for 6 weeks) (23 patients) or placebo (24 patients) in combination with a standard five-drug, second-line antituberculosis regimen. The primary efficacy end point was the conversion of sputum cultures, in liquid broth, from positive to negative. RESULTS: The addition of TMC207 to standard therapy for multidrug-resistant tuberculosis reduced the time to conversion to a negative sputum culture, as compared with placebo (hazard ratio, 11.8; 95% confidence interval, 2.3 to 61.3; P=0.003 by Cox regression analysis) and increased the proportion of patients with conversion of sputum culture (48% vs. 9%). The mean log(10) count of colony-forming units in the sputum declined more rapidly in the TMC207 group than in the placebo group. No significant differences in average plasma TMC207 concentrations were noted between patients with and those without culture conversion. Most adverse events were mild to moderate, and only nausea occurred significantly more frequently among patients in the TMC207 group than among patients in the placebo group (26% vs. 4%, P=0.04). CONCLUSIONS: The clinical activity of TMC207 validates ATP synthase as a viable target for the treatment of tuberculosis. (ClinicalTrials.gov number, NCT00449644.