China
Africa
Explore chapters and articles related to this topic
The Precision Medicine Approach in Oncology
Published in David E. Thurston, Ilona Pysz, Chemistry and Pharmacology of Anticancer Drugs, 2021
A biopsy is presently the only assured method to confirm diagnosis of an OC. Handheld devices that emit light of variable wavelengths are available to dentists that result in reflectance from, and/or autofluorescence of, the oral mucosa to more readily visualize OC lesions. However, high-quality clinical data to support the use of these devices to increase diagnostic accuracy or assist in the decision-making process are lacking. Therefore, there is significant interest in identifying molecular biomarkers that might be identified in saliva samples for screening and diagnosis purposes, and for monitoring disease progression during or after treatment.
Application of Wideband Acoustic Immittance (WAI) in Assessment of the Middle Ear in Newborns, Children, and Adults
Published in Stavros Hatzopoulos, Andrea Ciorba, Mark Krumm, Advances in Audiology and Hearing Science, 2020
At the end of this chapter the readers should be able to: Explain Wideband Acoustic Immittance (WAI) and its similarities and differences to conventional tympanometry.Analyze WAI patterns in normal and different middle ear pathologies.Differentiate WAI patterns between different age groups and different middle ear pathologies.Define absorbance and reflectance.Compare WAI with tympanometric outcomes in normal ears and ears with different middle ear pathologies.Understand the pros and cons of WAI in the assessment of middle ear function.Identify the limitation of middle ear analysis techniques and identify areas for future research direction.
Liver Microcirculation
Published in John H. Barker, Gary L. Anderson, Michael D. Menger, Clinically Applied Microcirculation Research, 2019
The principle of laser Doppler flowmetry is that an infrared laser with a wavelength of 780 ± 20 nm (1.6 mW) emits and penetrates up to 1 mm. Optical fibers of the flow probe conduct the laser beam to the tissue and the reflected light back to the photodetectors. Since the photons interact with moving red blood cells and stationary tissue cells, the portion of photons reflected and Doppler shifted indicates proportionally the moving microvascular blood volume and, by the frequency, the red blood cell velocity without indication of flow direction. A laser Doppler blood perfusion monitor and a flow probe available in different angles may be used for investigation of the liver surface following laparotomy.57 However, absolute measurements of blood flow are questionable so that relative measurements are recommended.58 Thus, LDF allows for monitoring tissue perfusion when a sufficient number of representative areas are scanned.59 For reflectance spectrophotometry in vivo, see previous section.
Mathematical and computational modeling for the determination of optical parameters of breast cancer cell
Published in Electromagnetic Biology and Medicine, 2021
Shadeeb Hossain, Shamera Hossain
Reflectance measurement allows scope for calibration of sensors and remote sensing (Di Girolamo 2003; Martonchik et al. 2000; Nicodemus et al. 1977; Schaepman-Strub et al. 2006). The concept of scattering parameter (S-parameter) is utilized to derive the reflectance magnitude. The scattering parameters correlate with reflection and transmission behavior of applied electromagnetic wave incident on dielectric malignant tissue sample (Salomatina et al. 2006). The S11 parameter is reflection measurement and explicates the evanescent and discontinuity behavior of polarized electromagnetic wave incident on boundary of dissimilar dielectric parameter. The nuance between Stoke’s relation and S-parameter includes the assumption of no EM absorption by system. However, a pragmatic representation has to peruse the absorption property because malignant tissues have a higher absorption property than its surrounding normal counterparts (Hossain 2020a, 2020b). The quantitative optical parameter distinction has prospective applications in technological advancement in optimized drug delivery procedures to target tumor sites or accurate diagnosis (Hossain 2018, 2020c; Hossain and Abdelgawad 2020; Hossain et al. 2019; Hu et al. 2018).
Residence time and mixing capacity of a rotary tablet press feed frame
Published in Drug Development and Industrial Pharmacy, 2021
Maren Zimmermann, Markus Thommes
The measurement was conducted in reflectance mode. Thereby the reflected light intensity was compared to the initial emitted light intensity. The ratio as a function of the wavelength was called spectra. In all cases, a white tablet consisting of the model formulation served as reference on which the system was calibrated a priori. Therefore, the conducted determination of the light intensity ratio defined as reflection rate R was a relative measurement. R was attenuated by the weight fraction of the UV-sensitive tracer (theophylline) (Figure 2, left). For further processing, the absorbance was calculated from the reflection rate R by using the Schuster–Kubelka–Munk equation (Equation (10)) at the maximum molar attenuation coefficient (272 nm). The equation was found for calculating absorption and scattering of light on solid layers [36].
Understanding the impact of magnesium stearate variability on tableting performance using a multivariate modeling approach
Published in Pharmaceutical Development and Technology, 2020
Ting Wang, Ahmed Ibrahim, Stephen W. Hoag
The spectral properties of the MgSt samples were characterized in our previous study; a brief summary is given below and a detailed description is given by Wang et al. (2019). NIR Spectra were measured with a NIRS XDS Rapid Content Analyzer (Metrohm, Columbia, MD, USA) from 400 to 2500nm at a 0.5nm resolution. Each spectrum was the average of 32 scans in diffuse reflectance mode measured through the bottom of a clear glass vial (Shell vial, 4ml, Sun-Sri, Rockwood, TN, USA). Three samples from each lot were scanned and the samples were obtained from different locations (top, middle and bottom) in a sample container (1kg). The average spectra are used for each lot. Raman spectra were acquired using a portable FT-Raman analyzer (RamanID, Real-Time Analyzers, Inc., Middletown, CT, USA). The laser wavelength is 1064nm, with spectral coverage from 150–3500cm−1 and a resolution of 8cm−1. The spectra obtained were the result of average of 50 scans. The detector is the thermos-electrically cooled indium gallium arsenide (InGaAs) detector. Powder samples in glass vial were placed into a Light-tight compartment in horizontal position. The spectra used for analysis are an average of three sample spectra.