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You searched for +publisher:"Clemson University" +contributor:("Dr. Jeffrey N. Anker"). Showing records 1 – 3 of 3 total matches.

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Clemson University

1. Rogalski, Melissa M. Development of Position-Dependent Luminescent Sensors: Spectral Rulers and Chemical Sensing Through Tissue.

Degree: PhD, Chemistry, 2016, Clemson University

Assessing the performance of medical devices is critical for understanding device function and monitoring pathologies. With the use of a smart device clinically relevant chemical and mechanical information regarding fracture healing may be deduced. For example, strain on the device may be used as a mechanical indicator of weight-bearing capacity. In addition, changes in chemical environment may indicate the development of implant associated infections. Although optical methods are widely used for ex vivostrain/motion analysis and for chemical analyses in cells and histological tissue sections, there utility is limited through thick tissue because light scattering reduces spatial resolution. This dissertation presents four novel luminescent sensors that overcome this limitation. The sensors are capable of detecting chemical and physical changes by measuring position or orientation-dependent color/wavelength changes through tissue. The first three sensors are spectral rulers comprised of two patterned thin films: an encoder strip and an analyzer mask. The encoder strip is either a thin film patterned with stripes of alternating luminescent materials (quantum dots, particles or dyes) or a film containing alternating stripes of a dye that absorbs luminescence from a particle film placed below. The analyzer mask is patterned with a series of alternating transparent windows and opaque stripes equal in width to the encoder lines. The analyzer is overlaid upon the encoder strip such that displacement of the encoder relative to the analyzer modulates the color/spectrum visible through the windows. Relative displacement of the sensor layers is mechanically confined to a single axis. When the substrates are overlaid in the “home position” one line spectrum is observed, and in the “end position,” another line spectrum is observed. At intermediate positions, spectra are a linear combination of the “home” and “end” spectra. The position-modulated signal is collected by a spectrometer and a spectral intensity ratio from closely spaced emission peaks is calculated. By collecting luminescent spectra, rather than imaging the device surface, the sensors eliminate the need to spatially resolve small features through tissue by measuring displacement as a function of color. We measured micron scale displacements through at least 6 mm of tissue using three types of spectral ruler based upon 1) fluorescence, 2) x-ray excited optical luminescence (XEOL), and 3) near infrared upconversion luminescence. The sensors may be used to investigate strain on orthopedic implants, study interfragmentary motion, or assess tendon/ligament tears. In addition to monitoring mechanical strain it is important to investigate clinically relevant implant pathologies such as infection. To address this application, we have developed a fourth type of sensor. The sensor monitors changes in local pH, an indicator of biofilm formation, and uses magnetic fields to modulate position and orientation-dependent luminescence. This modulation allows the sensor signal to be… Advisors/Committee Members: Dr. Jeffrey N. Anker, Committee Chair, Dr. John D. DesJardins, Dr. George Chumanov, Dr. Joseph Kolis.

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APA (6th Edition):

Rogalski, M. M. (2016). Development of Position-Dependent Luminescent Sensors: Spectral Rulers and Chemical Sensing Through Tissue. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/1706

Chicago Manual of Style (16th Edition):

Rogalski, Melissa M. “Development of Position-Dependent Luminescent Sensors: Spectral Rulers and Chemical Sensing Through Tissue.” 2016. Doctoral Dissertation, Clemson University. Accessed November 25, 2020. https://tigerprints.clemson.edu/all_dissertations/1706.

MLA Handbook (7th Edition):

Rogalski, Melissa M. “Development of Position-Dependent Luminescent Sensors: Spectral Rulers and Chemical Sensing Through Tissue.” 2016. Web. 25 Nov 2020.

Vancouver:

Rogalski MM. Development of Position-Dependent Luminescent Sensors: Spectral Rulers and Chemical Sensing Through Tissue. [Internet] [Doctoral dissertation]. Clemson University; 2016. [cited 2020 Nov 25]. Available from: https://tigerprints.clemson.edu/all_dissertations/1706.

Council of Science Editors:

Rogalski MM. Development of Position-Dependent Luminescent Sensors: Spectral Rulers and Chemical Sensing Through Tissue. [Doctoral Dissertation]. Clemson University; 2016. Available from: https://tigerprints.clemson.edu/all_dissertations/1706


Clemson University

2. Wen, Yimei. Synthesis, Application and Protein Nanomaterial Interactions of Selected Nanofiber, Nanoparticle and Nanoarray.

Degree: PhD, Chemistry, 2017, Clemson University

Nanomaterials have been a hot research topic for past decades due to their unique optical, electronic, catalytic and mechanical properties. This dissertation aims to investigate selected aspects of nanomaterial synthesis, application and protein nanomaterial interactions. We target to improve nanomaterials synthesis, explore their novel applications and study their potential hazardous. Chapter 1 describes new hydrothermal synthesis of carbon nanofibers from cellulose nanocrystals. The described hydrothermal synthesis from cellulose is an environmentally friendly method that has commercial potential for inexpensive production of carbon nanofibers. Chapter 2 describes the application of poly(methyl methacrylate) (PMMA) stabilized 2D AgNP array for measuring changes of bulk refractive index and sensing of selected volatile organic compound (VOC). The PMMA stabilized 2D AgNP array gives linear response to bulk refractive index changes and can be re-used after rinsing with water. Responsive polymer films were spin-coated on PMMA stabilized 2D AgNP array to fabricate the nanocomposite films. These nanocomposite films exhibit sharp coherent plasmon coupling, spectra position of which is affected by the changes of local dielectric environment when interacting with VOC vapors. Chapter 3 describes studies related to the interaction of AgNP and AuNP with cytoskeleton protein (actin and tubulin), immune system protein (complementary component 3) and plasma protein (albumin and fibronegen). The nanoparticle protein interaction is influenced by both nanoparticle and protein sizes. The work presented here establishes basic knowledge related to nanomaterial synthesis and their advanced applications. Advisors/Committee Members: Dr. George Chumanov, Committee Chair, Dr. R. Kenneth Marcus, Dr. Jeffrey N. Anker, Dr. William T. Pennington.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Wen, Y. (2017). Synthesis, Application and Protein Nanomaterial Interactions of Selected Nanofiber, Nanoparticle and Nanoarray. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/2042

Chicago Manual of Style (16th Edition):

Wen, Yimei. “Synthesis, Application and Protein Nanomaterial Interactions of Selected Nanofiber, Nanoparticle and Nanoarray.” 2017. Doctoral Dissertation, Clemson University. Accessed November 25, 2020. https://tigerprints.clemson.edu/all_dissertations/2042.

MLA Handbook (7th Edition):

Wen, Yimei. “Synthesis, Application and Protein Nanomaterial Interactions of Selected Nanofiber, Nanoparticle and Nanoarray.” 2017. Web. 25 Nov 2020.

Vancouver:

Wen Y. Synthesis, Application and Protein Nanomaterial Interactions of Selected Nanofiber, Nanoparticle and Nanoarray. [Internet] [Doctoral dissertation]. Clemson University; 2017. [cited 2020 Nov 25]. Available from: https://tigerprints.clemson.edu/all_dissertations/2042.

Council of Science Editors:

Wen Y. Synthesis, Application and Protein Nanomaterial Interactions of Selected Nanofiber, Nanoparticle and Nanoarray. [Doctoral Dissertation]. Clemson University; 2017. Available from: https://tigerprints.clemson.edu/all_dissertations/2042

3. Zimmerman, Matthew Todd. Determining DNA Damage Prevention Mechanisms for Multifunctional Selenium and Sulfur Antioxidants and the DNA-Damaging Capabilities of Clotrimadozle and Pseudoephedrine-Derived Metal Complexes.

Degree: PhD, Chemistry, 2014, Clemson University

DNA damage by reactive oxygen species (ROS) is a cause of many chronic diseases. This work examines the ability of sulfur and selenium antioxidants to prevent oxidative DNA damage and the mechanisms for this activity. Although iron- and copper-generated hydroxyl radical are primary causes of damage under oxidative stress conditions, studies typically focus on ROS scavenging rather than antioxidant-metal binding as a mechanism for sulfur and selenium antioxidant behavior. Mass spectrometry studies of sulfur and selenoamino acids (Chapter 2) show that most form CuI and FeII complexes, regardless of their metal-mediated DNA damage prevention abilities. Because their electrochemical properties do not correlate to antioxidant activity, metal binding rather than ROS scavenging is the major mechanism for these sulfur and selenium antioxidants. DNA damage assays with N,N’-dimethylimazole thione (dmit) and selone (dmise) determined that both prevent CuI-mediated DNA damage (IC50 = 1550 and ~240 µM, respectively; Chapter 3). Surprisingly, dmit and dmise more effectively inhibit FeII-mediated DNA damage (IC50 = 89.1 and 3.2 µM, respectively), an ability not previously observed for this class of antioxidants. Dmise and dmit coordinate CuI and FeII and prevent DNA damage by peroxynitrite (IC50 = 171.4 and 155.2, respectively). Studies with similar thiones, selones, and their derivatives (Chapter 4) showed that these compounds are also multifunctional antioxidants, preventing DNA damage by CuI (IC50= 22-1023 µM), FeII (IC50 = 2.3-1000 µM) and peroxynitrite (IC50 = 57.4-594 µM). Many of these compounds readily undergo oxidation and reduction, and mass spectrometry studies show CuI or FeII coordination, regardless of antioxidant activity. These are the first sulfur and selenium compounds with multifunctional antioxidant activity, and the structure-activity relationships established in this work will allow development of more potent antioxidants for disease treatment and prevention. Studies in Chapter 5 focus on how metal binding alters drug properties. Clotrimazole-metal complexes kill cancer cells, yet their cytotoxic mechanisms are not understood. Similarly, studies have not examined the effects of metal coordination on the biological properties of pseudoephedrine-derived compounds. DNA damage studies with copper complexes of both compounds found that they significantly damage DNA (EC50 = 10.5-21.7 µM), likely by copper-mediated ROS generation. Advisors/Committee Members: Dr. Julia L. Brumaghim, Committee Chair, Dr. Jeffrey N. Anker, Dr. Gautam Bhattacharyya, Dr. William T. Pennington.

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APA · Chicago · MLA · Vancouver · CSE | Export to Zotero / EndNote / Reference Manager

APA (6th Edition):

Zimmerman, M. T. (2014). Determining DNA Damage Prevention Mechanisms for Multifunctional Selenium and Sulfur Antioxidants and the DNA-Damaging Capabilities of Clotrimadozle and Pseudoephedrine-Derived Metal Complexes. (Doctoral Dissertation). Clemson University. Retrieved from https://tigerprints.clemson.edu/all_dissertations/1759

Chicago Manual of Style (16th Edition):

Zimmerman, Matthew Todd. “Determining DNA Damage Prevention Mechanisms for Multifunctional Selenium and Sulfur Antioxidants and the DNA-Damaging Capabilities of Clotrimadozle and Pseudoephedrine-Derived Metal Complexes.” 2014. Doctoral Dissertation, Clemson University. Accessed November 25, 2020. https://tigerprints.clemson.edu/all_dissertations/1759.

MLA Handbook (7th Edition):

Zimmerman, Matthew Todd. “Determining DNA Damage Prevention Mechanisms for Multifunctional Selenium and Sulfur Antioxidants and the DNA-Damaging Capabilities of Clotrimadozle and Pseudoephedrine-Derived Metal Complexes.” 2014. Web. 25 Nov 2020.

Vancouver:

Zimmerman MT. Determining DNA Damage Prevention Mechanisms for Multifunctional Selenium and Sulfur Antioxidants and the DNA-Damaging Capabilities of Clotrimadozle and Pseudoephedrine-Derived Metal Complexes. [Internet] [Doctoral dissertation]. Clemson University; 2014. [cited 2020 Nov 25]. Available from: https://tigerprints.clemson.edu/all_dissertations/1759.

Council of Science Editors:

Zimmerman MT. Determining DNA Damage Prevention Mechanisms for Multifunctional Selenium and Sulfur Antioxidants and the DNA-Damaging Capabilities of Clotrimadozle and Pseudoephedrine-Derived Metal Complexes. [Doctoral Dissertation]. Clemson University; 2014. Available from: https://tigerprints.clemson.edu/all_dissertations/1759

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