Fluorescence Spectral Features of Blood Components of Pregnant Women

Abstract

End-to-end research evaluation needs to separate out the bibliometric part of the chain from the econometric part. Both size-dependent and size-independent terms play a crucial role to combine quantity and quality (impact) in a meaningful way. Output or outcome at the bibliometric level can be measured using zeroth, first or secondorder composite indicators, and the productivity terms follow accordingly using the input to output or outcome factors.

Autofluorescence of blood and its application in biomedical and clinical research

“…This is due to different variants of hemoglobin and their subunits (Alpert et al, 1980;Hirsch et al, 1980;Zhurova et al, 2014). Hemoglobin seemingly emits strong fluorescence at 438 nm upon two-photon excitation by femtosecond pulses in the range 600-750 nm (Bukara et al, 2017;Zheng et al, 2011) and this feature has been explored for label-free imaging of T A B L E 1 List of some endogenous fluorophores along with their autofluorescence spectral range and their origin in either blood components or tissue (Croce & Bottiroli, 2014;Datta et al, 2020;de Oliveira Silva et al, 2010;Lowndes, 2010) Fluorophores Excitation (nm) Emission (nm) Source Implicated pathologies/unexplored potential impactful pathologies Porphyrins 400-450 630-700 Plasma, RBC Thalassemia (Devanesan et al, 2017), cancers (Masilamani et al, 2004) The autofluorescence emission characteristics of the fluorophore depends on the excitation wavelength.…”

“…The autofluorescence of tryptophan is influenced by the microenvironment and the emission maxima varies from 360 nm in aqueous highly polar solutions to 310 nm when its residues are buried inside the hydrophobic regions of proteins. The autofluorescence of haematoporphyrin depends on its polar form, as its basic form emits at 585 nm and the neutral form emits at 632 nm (Devanesan et al, 2017). Such a dependence of autofluorescence on factors other than physiological conditions raises a serious concern about their use to indicate a specific disease or diagnostic state, as the contribution of other factors cannot be ignored.…”

“…Therefore, the yellow‐orange and green autofluorescence evaluation of lymphocytes from buffy coat slides was used as a rapid and inexpensive secondary method to identify samples for later electron microscopy in the prescreening of neurodegenerative diseases (Hawkins et al, 1986). The combination of ES and SFS were used to study the plasma and formed element acetone extracts from normal, pregnant, and thalassemia patients (Devanesan et al, 2017). The emission intensity ratio of 632/585 nm of the extracts was able to discriminate between the three types of samples, due to the porphyrin concentrations being 80% higher in pregnant women and twofold lower in thalassemia patients compared to normal.…”

“…Regretfully, this area of application is currently under‐explored, with most studies focusing on acquired diseases such as cancer and infection. Initial studies have demonstrated that autofluorescence of blood and its components can detect alterations due to inherited blood disorders, primarily in hemoglobinopathies including sickle cell anemia (Ojaghi et al, 2020) and thalassemia (Devanesan et al, 2017). However, the clinical onset of these disorders, primarily due to the transition from gamma globin chains to beta globin chains until approximately 6 months postpartum, could limit the immediate application of this technique for screening in newborns.…”