Professor of Chemistry

Phone Number: 502-852-7061 (Office)
Email mcyapp01@louisville.edu

Address: Department of Chemistry
University of Louisville
Louisville, KY 40292

Additional Appointments:

• Associate Appointment, Dept. of Ophthalmology and Visual Sciences
• Director of Graduate Studies in Chemistry
• Member, American Chemical Society
• Member, Association for Research in Vision and Ophthalmology
• Member, Biophysical Society

Education:

• 1978 B.S.   Universidad Nacional del Litroal, Argentina
• 1985 Ph.D. Oregon State University

Research Focus:

One of our research themes is the development and application of spectrochemical analytical approaches for the selective determination and quantitation of species in complex matrices, particularly those of biological interest. As an example, we are applying laser induced fluorescence, UV-visible absorption, Fourier transform infrared, and more recently NMR spectroscopies to study, at the molecular level, processes which may lead to the formation of cataracts in human lenses. Fiber optical sensors have been used in conjunction with laser induced fluorescence to map the distribution of extrinsic fluorophores in human lenses. Changes in protein secondary structure are being investigated by monitoring the conformation-sensitive Amide I band region of the infrared spectrum. This broad band is the result of the overlap of bands corresponding to each structural component, i.e., {alpha}-helix, {beta}-sheet, {beta} turns and random coil. The resolution of these bands is achieved by applying computa-tional procedures, such as derivative spectroscopy and the nonlinear adaptation of the Kalman filter.

The theoretical and experimental characterization of fiber optical sensors is another area of our research. These studies allow us to design more sensitive sensors and to control the size and location of the interrogated sample volumes. This type of information is particularly relevant in the application of optical sensors to biological samples that are not homogeneous and can be affected by the presence of the sensing device.

Besides the above areas of research, my students are actively involved in the development of instrumental accessories, and interface hardware and software. We interact very closely with the faculty in the Department of Ophthalmology. Separation procedures and biological assays necessary in our studies are often performed in the Department of Ophthalmology under the supervision of Dr. Douglas Borchman, who has collaborated with us since 1987.

Selected Publications:

• Mudgil P, Borchman D, Gerlach D, Yappert MC. Sebum/Meibum Surface Film Interactions and Phase Transitional Differences. Invest Ophthalmol Vis Sci. 2016 May 1;57(6):2401-11. PubMed PMID: 27145473.
• Ivanova S, Tonchev V, Yokoi N, Yappert MC, Borchman D, et al. Surface Properties of Squalene/Meibum Films and NMR Confirmation of Squalene in Tears. Int J Mol Sci. 2015 Sep 9;16(9):21813-31. PubMed PMID: 26370992; PubMed Central PMCID: PMC4613282.
• Hunter M, Bhola R, Yappert MC, Borchman D, Gerlach D. Pilot study of the influence of eyeliner cosmetics on the molecular structure of human meibum. Ophthalmic Res. 2015;53(3):131-5. PubMed PMID: 25720840.
• Dalfovo MC, Lacconi GI, Moreno M, Yappert MC, Sumanasekera GU, et al. Synergy between graphene and Au nanoparticles (heterojunction) towards quenching, improving Raman signal, and UV light sensing. ACS Appl Mater Interfaces. 2014 May 14;6(9):6384-91. PubMed PMID: 24749787.
• Borchman D, Yappert MC, Milliner SE, Smith RJ, Bhola R. Confirmation of the presence of squalene in human eyelid lipid by heteronuclear single quantum correlation spectroscopy. Lipids. 2013 Dec;48(12):1269-77. PubMed PMID: 24081494.
• Mudgil P, Borchman D, Yappert MC, Duran D, Cox GW, et al. Lipid order, saturation and surface property relationships: a study of human meibum saturation. Exp Eye Res. 2013 Nov;116:79-85. PubMed PMID: 23973715.
• Borchman D, Yappert MC, Milliner SE, Duran D, Cox GW, et al. 13C and 1H NMR ester region resonance assignments and the composition of human infant and child meibum. Exp Eye Res. 2013 Jul;112:151-9. PubMed PMID: 23644094.
• Faheem S, Kim SH, Nguyen J, Neravetla S, Ball M, Foulks GN, Yappert MC, Borchman D. Wax-tear and meibum protein, wax-β-carotene interactions in vitro using infrared spectroscopy. Exp Eye Res. 2012 Jul;100:32-9. PubMed PMID: 22564968; NIHMSID: NIHMS373869; PubMed Central PMCID: PMC3575094.
• Borchman D, Foulks GN, Yappert MC, Milliner SE. Changes in human meibum lipid composition with age using nuclear magnetic resonance spectroscopy. Invest Ophthalmol Vis Sci. 2012 Jan 31;53(1):475-82. PubMed PMID: 22169100; PubMed Central PMCID: PMC3292379.
• Borchman D, Foulks GN, Yappert MC, Milliner SE. Differences in human meibum lipid composition with meibomian gland dysfunction using NMR and principal component analysis. Invest Ophthalmol Vis Sci. 2012 Jan 25;53(1):337-47. PubMed PMID: 22131391; PubMed Central PMCID: PMC3292369.
• Shrestha RK, Borchman D, Foulks GN, Yappert MC, Milliner SE. Analysis of the composition of lipid in human meibum from normal infants, children, adolescents, adults, and adults with meibomian gland dysfunction using ¹H-NMR spectroscopy. Invest Ophthalmol Vis Sci. 2011 Sep 21;52(10):7350-8. PubMed PMID: 21849420; PubMed Central PMCID: PMC3183971.
• Borchman D, Foulks GN, Yappert MC, Bell J, Wells E, et al. Human meibum lipid conformation and thermodynamic changes with meibomian-gland dysfunction. Invest Ophthalmol Vis Sci. 2011 Jun 1;52(6):3805-17. PubMed PMID: 21398284; PubMed Central PMCID: PMC3109056.