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Education

• Ph.D. Biomedical Engineering, Purdue University
• B.S. Chemical Engineering, Florida State University

Research

My research focuses on the development and application of optical imaging and illumination technologies to provide novel biomedical and clinical imaging and detection methods. Specific interests include the application of hyperspectral imaging and analysis methods to microscopy, endoscopy, and small-animal fluorescence imaging. My research has included the design of spectral small animal fluorescence imaging systems, optical tissue phantoms for imager calibration, spectral image analysis techniques, and novel endoscopic techniques that are complimentary to hyperspectral and microscopic imaging modalities. My current research efforts focus on translation of hyperspectral imaging technologies to real-time clinical diagnostic devices with a large improvement in detection sensitivity and specificity, and a low cost.

Publications

• Craig M. Browning, Samantha Mayes, Samuel A. Mayes, Thomas C. Rich, Silas J. Leavesley. Microscopy is better in color: development of a streamlined spectral light path for real-time multiplex fluorescence microscopy. Biomedical Optics Express, (accepted – in press), PMCID: in process
• Aritra Bhadraad, April K. Scruggs, Silas J. Leavesley, Naga Annamdevula, April H. George, Andrea L. Britain. Christopher M. Francis, Jennifer M. Knighten, Thomas C. Rich, Natalie N. Bauer. Extracellular vesicle-induced cyclic AMP signaling. Cellular Signaling 95 110348 (2022), PMCID: in process
• Thomas C. Rich, Silas J. Leavesley, Angela P. Brandon, Cilina A. Evans, S. Vamsee Raju,  Brant M. Wagener. Phosphodiesterase 4 mediates interleukin-8-induced heterologous desensitization of the β2-adrenergic receptor. FASEB Journal 35: e21946 (2021), PMCID: PMC8483573
• Ryan Warren, Thomas C. Rich, Silas J. Leavesley, Anh-Vu Phan. A three-dimensional finite element model of cAMP signals. Forces in Mechanics, 4 100041 (2021), PMCID: PMC8773462
• Kevin J. Lee, Wen-Chi L. Chang, Xi Chen, Jacob Valiyaveettil, Veronica Ramirez-Alcantara, Elaine Gavin, Alla Musiyenko, Luciana Madeira da Silva, Naga S. Annamdevula, Silas J. Leavesley, Antonio Ward, Tyler E. Mattox, Ashley S. Lindsey, Joel Andrews, Bing Zhu, Charles Wood, Ashleigh Neese, Ashley Nguyen, Kristy Berry, Yulia Maxuitenko, Mary P. Moyer, Elmar Nurmemmedov, Greg Gorman, Lori Coward, Gang Zhou, Adam B. Keeton, Harry S. Cooper, Margie L. Clapper. Suppression of colon tumorigenesis in mutant Apc mice by a novel PDE10 inhibitor that reduces oncogenic β-catenin. Cancer Prevention Research, (accepted – in press), PMCID: in process
• Craig M. Browning, Joshua Deal, Sam Mayes, Arslan Arshad, Thomas C. Rich, Silas J. Leavesley. Excitation-scanning hyperspectral video endoscopy: enhancing the light at the end of the tunnel. Biomedical Optics Express, 12:1 247-271 (2021). PMCID: PMC7818959
• Naga S. Annamdevula, Rachel Sweat, Hayden Gunn, John R. Griswold, Andrea L. Britain, Thomas C. Rich, Silas J. Leavesley. Measurement of 3-Dimensional cAMP Distributions in Living Cells using 4-Dimensional (x, y, z, and λ) Hyperspectral FRET Imaging and Analysis. Journal of Visualized Experiments (JoVE), . J. Vis. Exp. 164 e61720 (2020). PMCID: PMC7968043 – Under Embargo
• Ron Balczon, K. Adam Morrow, Silas Leavesley, C. Michael Francis, Trevor C. Stevens, Ezinne Agwaramgbo, Christopher Williams, Reece P. Stevens, Geri Langham, Sarah Voth, Eugene A. Cioffi, Susan E. Weintraub, Troy Stevens. Cystatin C Regulates the Cytotoxicity of Infection-Induced Endothelial-Derived β Amyloid. FEBS Open Bio 10 2464-2477 (2020). PMCID: PMC7609779
• Joshua Deal, DJ Pleshinger, Santina C Johnson, Silas J Leavesley, Thomas C Rich. Milestones in the Development and Implementation of FRET-Based Sensors of Intracellular Signals: A Biological Perspective of the History of FRET. Cellular Signaling 75 109769 (2020). PMCID: PMC7679057
• Mikhail Alexeyev, Aron Geurts, Naga Annamdevula, C. Francis, Silas Leavesley, Thomas Rich, Mark Taylor, Mike Lin, Ron Balczon, Jennifer Knighten, Diego Alvarez, Troy Stevens. Development of an endothelial cell restricted transgenic reporter rat: A resource for physiological studies of vascular biology. American Journal of Physiology – Heart and Circulatory Physiology, 319:2 H349-H358 (2020). PMCID: PMC7473926
• Phoibe Renema, Kierra Hardy, Nicole Housley, Grace Dunbar, Naga Annamdevula, Andrea Britian, Domenico Spadafora, Silas Leavesley, Thomas Rich, Jonathan Audia, Diego Alvarez. cAMP signaling primes lung endothelial cells to activate caspase-1 during Pseudomonas aeruginosa infection. American Journal of Physiology – Lung Cellular and Molecular Physiology, 318:5 L1074-L1083 (2020). PMCID: PMC7272745
• Peter F. Favreau, Joshua A. Deal, Bradley Harris, David S. Weber, Thomas C. Rich, Silas J. Leavesley. Label-free spectroscopic tissue characterization using fluorescence excitation-scanning spectral imaging. Journal of Biophotonics, 13:e201900183 (2020). PMCID: PMC8491137  Journal front cover
• N. Stone, S. Shettlesworth, Thomas C. Rich, Silas J. Leavesley, and Anh-Vu Phan. A Two-Dimensional Finite Element Model of Cyclic Adenosine Monophosphate (CAMP) Intracellular Signaling. SN Applied Sciences 1, no. 12 (2019): 1713. PMCID: PMC7891547
• Joshua Deal, Andrea Britain, Thomas Rich, Silas Leavesley. Excitation-Scanning Hyperspectral Imaging Microscopy to Efficiently Discriminate Fluorescence Signals. Journal of Visualized Experiments (JoVE), https://www.jove.com/video/59448/. J. Vis. Exp. 150 e59448 (2019). PMCID: PMC6800214
• Joshua Deal, Sam Mayes, Craig Browning, Shante Hill, Paul Rider, Carole Boudreaux, Thomas C. Rich, Silas J. Leavesley. Identifying molecular contributors to autofluorescence of neoplastic and normal colon sections using excitation-scanning hyperspectral imaging. Journal of Biomedical Optics 24:2 021207 (2018), PMCID: PMC6307688
• Mike T. Lin , Ron Balczon , Jean-Francois Pittet , Brant M. Wagener , Stephen A. Moser , K. Adam Morrow , Sarah Voth , C. Michael Francis , Silas Leavesley, Jessica Bell , Diego F. Alvarez , and Troy Stevens. Nosocomial Pneumonia Elicits an Endothelial Proteinopathy: Evidence for a Source of Neurotoxic Amyloids in Critically Ill Patients. American Journal of Respiratory and Critical Care Medicine 198:12 1575-1578 (2018), PMCID: PMC6298632 [see commentary: Yvonne S. Eisele, Amyloidosis by Bacterial Infection in Critically Ill Patients? American Journal of Respiratory and Critical Care Medicine 198:12 1475-1476 (2018)]
• Naga S. Annamdevula, Rachael Sweat, John R. Griswold, Kenny Trinh, Chase Hoffman, Savannah West, Joshua Deal, Andrea L. Britain, Kees Jalink, Thomas C. Rich, and Silas J. Leavesley. Spectral imaging of FRET-based sensors reveals sustained cAMP gradients in three spatial dimensions. Cytometry, Part A 93:10 1029-1038 (2018), PMCID: PMC6512796
• David Nelson, Silas Leavesley, Carmen Zirlott, Xi-ming Yang, James Downey. Feasibility of Using Thermal Response to Ka Band Millimeter Wave Heating to Assess Skin Blood Flow. Physiological Measurement 39:4 045001-1 – 045001-9 (2018)
• Ron Balczon, Michael Francis, Silas Leavesley, Troy Stevens, Methods for detecting cytotoxic amyloids following infection of pulmonary endothelial cells by pseudomonas aeruginosa. J. Vis. Exp. 137 e57447 (2018), PMCID: PMC6126449
• Yuanyuan Xu, Yu-Qing Jiang, Ce Li, Mindi He, W. George Rusyniak, Naga Annamdevula, Juan Ochoa, Silas J Leavesley, Jiangping Xu, Thomas C Rich, Mike T Lin1, Xiang-ming Zha. Human ASIC1a mediates stronger acid-induced responses as compared to mouse ASIC1a. FASEB Journal 32, 3832–3843 (2018), PMCID: PMC5998965
• Silas J. Leavesley, Brenner Sweat, Caitlyn Abbott, Peter Favreau, and Thomas C. Rich. A theoretical-experimental methodology for assessing the sensitivity of biomedical spectral imaging platforms, assays, and analysis methods. Journal of Biophotonics 11:1 1-25 (2018), PMCID: PMC5680159 Journal front cover
• Ron Balczon, K. Adam Morrow, Chun Zhou, Bradley Edmonds, Mikhail Alexeyev, Jean-Francois Pittet, Brant M. Wagener, Stephen A. Moser, Silas Leavesley, Xiangming Zha, Dara W. Frank, and Troy Stevens. Pseudomonas aeruginosa infection liberates transmissible, cytotoxic prion amyloids. FASEB Journal 31:7 2785-2796 (2017), PMCID: PMC5471513
• Silas J. Leavesley, Mikayla Walters, Carmen Lopez, Thomas Baker, Peter F. Favreau, Thomas C. Rich, Paul F. Rider, Carole W. Boudreaux. Hyperspectral imaging fluorescence excitation-scanning for colon cancer detection. Journal of Biomedical Optics, 21:10 104003-1 – 104003-11 (2016), PMCID: PMC5084534
• Silas J. Leavesley, Thomas C. Rich. Overcoming limitations of FRET measurements. Cytometry, Part A 89:4 325-327 (2016), PMCID: PMC5835960 *Invited, peer-reviewed commentary
• Wenkuan Xin, Wei P. Feinstein, Andrea L. Britain, Cristhiaan D. Ochoa, Bing Zhu, Wito Richter, Silas J. Leavesley, and Thomas C. Rich. Estimating the magnitude of near-membrane PDE4 activity in living cells. American Journal of Physiology – Cell Physiology, 309:6 C415-C424 (2015), PMCID: PMC4572370
• Meagan A. Bunge, K. Neil Ruckart, Silas J. Leavesley, Gregory W. Peterson, Nien Nguyen, Kevin N. West, T. Grant Glover. Modification of fibers with nanostructures using reactive dye chemistry.   Industrial & Engineering Chemistry Research, 54:15 3821–3827 (2015)
• Silas J. Leavesley, Thomas C. Rich. FRET: Signals hidden within the noise. Cytometry, Part A, 85:11 918-920 (2014), PMCID: PMC4360877 *Invited, peer-reviewed commentary
• Peter F. Favreau, Clarissa Hernandez, Tiffany Heaster, Diego F. Alvarez, Thomas C. Rich, Prashant Prabhat, & Silas J. Leavesley. An excitation-scanning hyperspectral imaging microscope. Journal of Biomedical Optics, 19:4 046010-1 – 046010-10 (2014)
• Silas J. Leavesley, Whitley Ledkins, Petra Rocic. A device for performing automated balloon catheter inflation ischemia studies. PLOS ONE, 9:4 e95823-1 – e95823-10 (2014)
• Thomas C. Rich, Kristal Webb, Silas J. Leavesley. Perspectives on Cyclic Nucleotide Microdomains and Signaling Specificity: Can we decipher the information content contained within cyclic nucleotide signals? Journal of General Physiology, 143:17-27 (2014)
• Peter Favreau, Clarissa Hernandez, Ashley Stringfellow Lindsey, Diego F. Alvarez, Thomas C. Rich, Prashant Prabhat, Silas J. Leavesley. Tunable thin-film optical filters for hyperspectral microscopy. Journal of Biomedical Optics, 19:1 011017-1 – 011017-11 (2014)
• Naga S. Annamdevula, Brenner Sweat, Peter Favreau, Ashley S. Lindsey, Diego F. Alvarez, Thomas C. Rich, Silas J. Leavesley. An approach for characterizing and comparing hyperspectral microscopy systems. Sensors, 13:7 9267-9293 (2013)
• Silas J. Leavesley, Andrea Britain, Lauren Cichon, Thomas C. Rich. Assessing FRET using spectral techniques. Cytometry, Part A, 83:10 898-912 (2013) [see commentary: Schneckenburger H. Commentary: Assessing FRET using spectral techniques. Cytometry A. 83:896-897 (2013)]
• Sanjeev K. Srivastava, Arun Bhardwaj, Silas J. Leavesley, William E. Grizzle, Seema Singh, Ajay P. Singh. MicroRNAs as potential clinical biomarkers: emerging approaches for their detection. Biotechnic and Histochemistry 88:7 373-387 (2013)
• Wei P. Feinstein, Bing Zhu, Silas J. Leavesley, Sarah L. Saynor, Thomas C. Rich. Assessment of cellular mechanisms contributing to cAMP compartmentalization in pulmonary microvascular endothelial cells. American Journal of Physiology – Cell Physiology 302:6 C839-C852 (2012) [see commentary: Murray, F. Am. J. Physiol. Cell Physiol. 302:C837-C838 (2012)]
• Silas J. Leavesley, Naga Annamdevula, John Boni, Samantha Stocker, Kristin Grant, Boris Troyanovsky, Thomas C. Rich, Diego F. Alvarez. Hyperspectral imaging microscopy for identification and quantitative analysis of fluorescently labeled cells in highly autofluorescent tissue. Journal of Biophotonics 5:1 67-84 (2012) Journal back cover
• Silas J. Leavesley, Kevin N. West. A graduate laboratory course on biodiesel production: emphasizing professional, teamwork, and research skills. Chemical Engineering Education 45:4 248-256 (2011) Featured graduate education article

Patents

• Silas Leavesley. Spectral illumination device and method (International Patent Application #PCT/US13/53787, Provisional patent, Docket #2012-013-ENG, international patent submitted)
• Heidi Hall, Mark Edward Bridges, Silas J. Leavesley, Valeri P. Patsekin, J. Paul Robinson, David L. Patton, Douglas Lincoln Vizard, William E. McLaughlin, Bartlomeiej P. Rajwa. Apparatus and method for multi-modal imaging using nanoparticle multi-modal imaging probes. (applied for, United States Patent Application Number: US 2009/0093700 A1)
• Silas Leavesley, Peng Xi, J. Paul Robinson. Endoscopic imaging device.  United States Patent Publication Number: US 8251896 B2.  International Patent Publication Number: WO/2007/041383
• Silas Leavesley, Peng Xi, J. Paul Robinson. Endoscopic imaging device.  United States Patent Publication Number: US 8777846 B2 (additional claims and expanding coverage to US 8251896 B2).

Courses

• EG 101 Introduction to Engineering and Design
• CHE 311 Equilibrium Stage Operations
• CHE 342 Engineering Communications
• CHE 352 Process Measurement Lab II
• CHE 372 Chemical Reactor Design
• EG 620 Biomedical Instrumentation, Imaging, and Modeling