Sub-terahertz vibrational spectroscopy of ovarian cancer and normal control tissue for molecular diagnostic technology.

We introduce here recently developed highly resolved Sub-Terahertz resonance spectroscopy of biological molecules and cells combined with molecular dynamics (MD) computational analysis as a new approach for optical visualization and quantification of the presence of microRNAs, particularly the mir-200 family, as potential biomarkers in samples from tissue of epithelial ovarian cancers for disease early detection, analysis, prognosis and treatment.METHOD: A set of samples for this study was prepared from anonymized archival formalin-fixed, paraffin-embedded ovarian epithelial tissue containing regions of invasive neoplastic cells from cases of high-histologic grade serous papillary ovarian carcinoma. Control samples were normal mucosa from fallopian tubes of patients with no known malignancy.

Sub-THz specific relaxation times of hydrogen bond oscillations in E.coli thioredoxin. Molecular dynamics and statistical analysis.

Hydrogen bonds (H-bonds) in biological macromolecules are important for the molecular structure and functions. Since interactions via hydrogen bonds are weaker than covalent bonds, it can be expected that atomic movements involving H-bonds have low frequency vibrational modes. Sub-Terahertz (sub-THz) vibrational spectroscopy that combines measurements with molecular dynamics (MD) computational prediction has been demonstrated as a promising approach for biological molecule characterization.

Molecular dynamics modeling of the sub-THz vibrational absorption of thioredoxin from E. coli.

Sub-terahertz (THz) vibrational modes of the protein thioredoxin in a water environment were simulated using molecular dynamics (MD) in order to find the conditions needed for simulation convergence, improve the correlation between experimental and simulated absorption frequencies, and ultimately enhance the predictive capabilities of computational modeling. Thioredoxin from E. coli was used as a model molecule for protocol development and to optimize the simulation parameters.

Terahertz absorption of DNA decamer duplex.

This work combines experimental and theoretical approaches to investigate terahertz absorption spectra of the DNA formed by the sequence oligomer 5'-CCGGCGCCGG-3'. The three-dimensional structure of this self-complimentary DNA decamer has been well-studied, permitting us to perform direct identification of the low-frequency phonon modes associated with specific conformation and to conduct comprehensive computer simulations. Two modeling techniques, normal-mode analysis and nanosecond molecular dynamics with explicit solvent molecules, were employed to extract the low-frequency vibrational modes based on which the absorption spectra were calculated.

Enhanced coupling of subterahertz radiation with semiconductor periodic slot arrays.

In this work, a theoretical study of the coupling of TM polarized subterahertz (THz) radiation with periodic semiconductor rectangular slot arrays was conducted, using InSb as an example. Simulation results showed that the structure with 4-12 microm thickness provides over a 20-30-fold increase in the electric field at slot edges in a nanosize region ( approximately 500 nm). The enhancement of the THz electromagnetic field extends across the slots and reaches peak values at the edges due to discontinuity effects.