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Optical Spectroscopy for the Detection of Necrotizing Enterocolitis
Published in David J. Hackam, Necrotizing Enterocolitis, 2021
Optical spectroscopy is a technology that has shown potential promise in this regard and merits more widespread understanding and investigation. Spectroscopy is a measurement of the interaction of electromagnetic radiation, or light, with tissue. The electromagnetic spectrum is the range of wavelengths and respective frequencies that light waves can manifest, spanning the following commonly known energies from lowest to highest: radio, microwave, infrared, visible (400–700 nm wavelength), ultraviolet, x-ray, and gamma (Figure 20.1). Whenever photons (the basic building blocks of electromagnetic radiation that have properties of both a particle and a wave) encounter an object, various fractions of the light are simultaneously reflected, absorbed, and scattered (Figure 20.2). The proportion of each of these fractions varies by wavelength and is determined by the characteristics of the target and its tendency to interact with each respective wavelength. A spectrophotometer is a device that quantifies this interaction by detecting the fraction of light that is either transmitted (i.e., not absorbed) or reflected. Spectrophotometers are widely used in a diverse array of scientific fields to characterize objects of interest, including physics, astronomy, materials science, chemistry, and biochemistry.
Rapid Methods in Cosmetic Microbiology
Published in Philip A. Geis, Cosmetic Microbiology, 2020
Optical spectroscopy is an analytical tool that measures the interactions between light and the material being studied. Light scattering is a phenomenon in which the propagation of light is disturbed by its interaction with particles. For example, “Mie scattering” is one form of light scattering in which scattered light is proportional to the particle size. Therefore, many particle counters employ Mie scattering to detect, count and size particles in an environment, such as those used in cleanrooms and other microbiologically controlled areas.
Check the Cancer Before It Checks You Out
Published in Prakash Srinivasan Timiri Shanmugam, Understanding Cancer Therapies, 2018
The interaction of light with tissues may highlight changes in tissue structure and metabolism. Optical spectroscopy systems to detect changes relying on the fact that the optical spectrum derived from a tissue will contain information about the histological and biochemical characteristics of that tissue. Such optical adjuncts may assist in the identification of mucosal lesions, including premalignant lesions and oral squamous cell carcinomas; may assist in biopsy site selection and enhance visibility of the surface texture and margins of lesions; and may also assist in the identification of cellular and molecular abnormalities not visible to the naked eye on routine examination. There are a number of optical systems that can yield similar types of information approaching the detail of histopathology, and theoretically at least, in a more quantifiable and objective fashion, in real-time, noninvasively, and in situ (Scully et al. 2008).
Human tear fluid analysis for clinical applications: progress and prospects
Published in Expert Review of Molecular Diagnostics, 2021
Sphurti S Adigal, Alisha Rizvi, Nidheesh V. Rayaroth, Reena V John, Ajayakumar Barik, Sulatha Bhandari, Sajan D George, Jijo Lukose, Vasudevan. B. Kartha, Santhosh Chidangil
In view of the research methodologies being employed at present, some pertinent procedures can be considered for further research and development. The three technologies being pursued at present, in increasing complexity, cost of equipment and expertise required, can be put in the order (i) optical spectroscopy (absorption, fluorescence, scattering), (ii) separation methods (HPLC/UPLC/SDS-PAGE) and mass spectroscopy, followed by (iii) hyphenated methods. It is thus appropriate to think how these three technologies can be coordinated. A suitable modus operandi can be: carry out universal screening using the optical spectroscopy technique, since it needs only trained technicians, can be coupled to automatic data processing to give objective conclusions, requires miniature portable/hand-held equipment only, and above all, preserves the same sample for further tests if warranted. Cases diagnosed as abnormal can then be sent for HPLC/UPLC studies, and if desired, or in case the specific marker identities will be useful for therapy planning and decision making, MS-dependent separation techniques can be used. Such a coordinated procedure will be most helpful for universal healthcare, especially, under low-resource settings.
Real-time fluorescence imaging for visualization and drug uptake prediction during drug delivery by thermosensitive liposomes
Published in International Journal of Hyperthermia, 2019
Anjan Motamarry, Ayele H. Negussie, Christian Rossmann, James Small, A. Marissa Wolfe, Bradford J. Wood, Dieter Haemmerich
In the current study with TSL–Dox, we present real-time in vivo fluorescence imaging methods for monitoring, and for quantification of tumor drug uptake. Dox is inherently fluorescent, and in vivo microscopy studies have exploited this property to monitor drug uptake at the microscopic level during delivery with TSL–Dox and to characterize drug penetration [8,26–28]. One study employed optical spectroscopy measurements obtained via a fiber-optic probe to quantitatively monitor tumor drug uptake [29]. Several groups have employed whole-body in vivo fluorescence imaging to visualize drug accumulation from TSL–Dox release after completion of HT. To our knowledge, there is no in vivo whole-body fluorescence imaging study that monitored spatial drug distribution in real-time during heating and delivery. The goals of this study were to demonstrate that (1) time lapse in vivo fluorescence imaging can be used to monitor drug uptake in real-time during HT mediated drug delivery, and (2) that in vivo fluorescence intensity can predict tumor Dox accumulation (Figure 1).
Real time evaluation of tissue optical properties during thermal ablation of ex vivo liver tissues
Published in International Journal of Hyperthermia, 2018
Vivek K. Nagarajan, Venkateswara R. Gogineni, Sarah B. White, Bing Yu
Temperature-based methods, such as the Arrhenius model [13,14], are commonly used to assess thermal tissue damage in real-time during tumor ablation [15–17]. However, temperature-based methods do not account for tissue heterogeneity, and require prior knowledge of tissue properties to determine the extent of thermal damage. Light propagation within a biological tissue is sensitive to the tissue morphology and physiology. Specifically, quantitative optical spectroscopy can determine the optical properties of normal vs. coagulated tissue, with higher µa(λ) and µs′(λ) seen in coagulated tissues [18–20]. Although changes in tissue optical properties are due to denaturation, the correlation between tissue absorption and reduced scattering coefficient and true tissue damage are yet to be established. Quantitative optical spectroscopy could therefore be performed to predict complete tissue ablation.