Optical Spectroscopy for the Detection of Necrotizing Enterocolitis
David J. Hackam in 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.
Infrared Spectroscopy
Adorjan Aszalos in Modern Analysis of Antibiotics, 2020
General technique and sample preparation have been discussed by a number of authors [1,2,5]. The methods of presenting antibiotics to the spectrophotometer is essentially the same as for other materials. Most commonly, a small amount of the sample (∼0.5%) is mixed with potassium bromide and compressed into a transparent disk. The disk is mounted in a holder and placed in the light path of the spectrophotometer. If the sample is hygroscopic, the mixture may be heated in vacuo at moderate temperatures to remove moisture. Frequently, a solid sample may be “mulled” with mineral oil, placed between salt plates, and run. This provides a rapid and convenient method of sample preparation.
Characterization Of Fluids And Gases
Sujoy K. Guba in Bioengineering in Reproductive Medicine, 2020
Light transmission spectrophotometry was first applied to amniotic fluid assessment by Liley.32 The parameter investigated was the bilirubin level. A spectrophotometer in the visible light range that is 350 to 700 nm wavelength was used. Liley33 had noted that the presence of meconium interfered with the absorption spectra. That is, meconium also absorbs light in the visible spectrum range. This observation was used by Molcho, et al.34 to estimate meconium levels in the amniotic fluid. Like Liley the optical density was measured in the wavelength range 350 to 700 nm. By studying simulated model solutions in which different amounts of meconium was added these investigators found that the peak of meconium absorption was at 410 nm with the spread of the absorbance from 370 nm to 450 nm.
Comparison of tiotropium delivery with the ODAPT adapter and a valved holding chamber
Published in Canadian Journal of Respiratory, Critical Care, and Sleep Medicine, 2021
Rym Mehri, Abubakar Alatrash, Nicholas Ogrodnik, Kenny Lee Slew, Edgar A. Matida
The experimental setup was then disassembled and washed separately to quantify the amount of medication deposited within each component. All the different components were washed using distilled water to dissolve the medication. The ACI deposition plates were placed into separate Petri dishes with 15 mL of distilled water and were shaken for 1 minute each. The face, facemask, and ODAPT adapter (for test case 3 and 4) were carefully cleaned with 10 mL, 10 mL and 8 mL of distilled water, respectively. The induction port (IP) only (for test case 1 and 2) or the IP and the tubing coupler (for the test case 3, 4, 5 and 6) were washed with 15 mL of distilled water. For test case 5 and 6, the VHC was washed using 25 mL of distilled water. Each component was left in their respective solution for 2 hours to allow for a consistent dissolution of the medication. Spectrophotometry was used to obtain the concentration of each solution at 237 nm (8453 UV-Visible Spectrophotometer, Agilent Technologies, Santa Clara, CA). Further details on the spectrophotometry methodology are provided in Mehri et al.15 Three repeats of each test were performed.
Arabian Primrose leaf extract mediated synthesis of silver nanoparticles: their industrial and biomedical applications
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2020
Shruti Nindawat, Veena Agrawal
The dyes namely methylene blue (MB), crystal violet (CV), methyl red (MR), methyl orange (MO), eosin yellow (EY), trypan blue (TB) and safranin O (SO) were subjected to sodium borohydride (NaBH4) reduction in the presence of Ah-AgNPs in order to assess the catalytic potential of nanoparticles. It was done according to the modified protocol of Nakkala et al. [12]. Briefly, 0.150 M NaBH4 solution was prepared and fresh solution was mixed with 1 mM dye (1 ml). To this, AgNPs suspension (50 µg/mL) was added and agitated well. UV-Vis spectrophotometer was used to scan the wavelength in the range 200–800 nm. For kinetic analysis, the change in absorbance at 662 nm, 585 nm, 394 nm, 460 nm, 515 nm, 594 nm and 516 nm for MB, CV, MR, MO, EY, TB and SO respectively, was recorded. The rate of reaction was determined by the equation given by Sengan et al. [13]: k is first-order rate constant, t is time duration of reaction, At is absorbance at time t and A0 is absorbance at time 0. The value of k (rate constant) was calculated from the slope of linear part of kinetics data.
Effect of casting solvent, film-forming agent and solubilizer on orodispersible films of a polymorphic poorly soluble drug: an in vitro/in silico study
Published in Drug Development and Industrial Pharmacy, 2019
Ahmed Abd El-Bary, Ibrahim Al Sharabi, Balqees Saeed Haza'a
Dissolution studies were carried out according to the USP dissolution II paddle method using a dissolution tester (Vision® Classic 6TM Dissolution Tester, Hanson Research Corporation, California, USA) using 900 mL of 0.1 N HCl as a dissolution medium. The rotation speed was 50 rpm and the temperature was kept at 37 ± 0.5 °C. A 5-mL sample was withdrawn and replaced with fresh dissolution media at specified time intervals. The collected samples were filtered through 0.45 μm Millipore filter papers to be analyzed for piroxicam content at 333 nm using the UV/Vis. Spectrophotometer. Stainless steel mesh with sieve opening of about 1 mm was used to dip the tested films inside the dissolution medium. All experiments were conducted in triplicate, and mean values ± SD were calculated. Percentages of drug released from the films were plotted as a function of time.
Related Knowledge Centers
- Biochemistry
- Chemistry
- Molecular Biology
- Photometer
- Reflectance
- Spectroscopy
- Ultraviolet
- Visible Spectrum
- X-Ray
- Monochromator